journal of civil engineering and architecture 2013

Journal of Civil Engineering

and Architecture

Volume 7, Number 10, October 2013 (Serial Number 71)

David Publishing Company

www.davidpublishing.com

PublishingDavid

Publication Information: Journal of Civil Engineering and Architecture is published monthly in hard copy (ISSN 1934-7359) and online (ISSN 1934-7367) by David Publishing Company located at 3592 Rosemead Blvd #220, Rosemead, CA 91770, USA.

Aims and Scope: Journal of Civil Engineering and Architecture, a monthly professional academic journal, covers all sorts of researches on structure engineering, geotechnical engineering, underground engineering, engineering management, etc. as well as other issues.

Editorial Board Members: Dr. Tamer A. El Maaddawy (Canada), Prof. San-Shyan Lin (China Taiwan), Dr. Songbai Cai (China), Dr. Xiaoyan Lei (China), Prof. Vladimir Patrcevic (Croatia), Dr. Sherif Ahmed Ali Sheta (Egypt), Prof. Nasamat Abdel Kader (Egypt), Prof. Mohamed Al-Gharieb Sakr (Egypt), Prof. Olga Popovic Larsen (Denmark), Prof. George C. Manos (Greece), Dr. Konstantinos Giannakos (Greece), Pakwai Chan (Hong Kong), Dr. K. Muthukkumaran (India), Chiara Vernizzi (Italy), Prof. Michele Maugeri (Italy), Dr. Giovanna Vessia (Italy), Prof. Valentina Zileska-Pancovska (Macedonia), Dr. J. Jayaprakash (Malaysia), Mr. Fathollah Sajedi (Malaysia), Prof. Nathaniel Anny Aniekwu (Nigeria), Dr. Marta Słowik (Poland), Dr. Rafael Aguilar (Portugal), Dr. Moataz A. S. Badawi (Saudi Arabia), Prof. David Chua Kim Huat (Singapore), Dr. Vail Karakale (Waiel Mowrtage) (Turky), Dr. A.Senem Deviren (Turkey), Dr. Yasemin Afacan (Turkey), Dr. Ming An (UK), Prof. Ahmed Elseragy (UK), Prof. Jamal Khatib (UK), Dr. John Kinuthia (UK), Dr. Johnnie Ben-Edigbe (UK), Dr. Yail Jimmy Kim (USA), Dr. Muang Seniwongse (USA), Prof. Xiaoduan Sun (USA), Dr. Zihan Yan (USA), Dr. Tadeh Zirakian (USA).

Manuscripts can be submitted via Web Submission, or E-mail to [email protected] or [email protected]. Submission guidelines and Web Submission system are available at http://www.davidpublishing.com, www.davidpublishing.org.

Editorial Office: 3592 Rosemead Blvd #220, Rosemead, CA 91770, USA Tel: 1-323-984-7526, 323-410-1082 Fax: 1-323-984-7374, 323-908-0457 E-mail: [email protected]; [email protected]; [email protected].

Copyright©2013 by David Publishing Company and individual contributors. All rights reserved. David Publishing Company holds the exclusive copyright of all the contents of this journal. In accordance with the international convention, no part of this journal may be reproduced or transmitted by any media or publishing organs (including various websites) without the written permission of the copyright holder. Otherwise, any conduct would be considered as the violation of the copyright. The contents of this journal are available for any citation. However, all the citations should be clearly indicated with the title of this journal, serial number and the name of the author.

Abstracted / Indexed in: Database of EBSCO, Massachusetts, USA Chinese Database of CEPS, Airiti Inc. & OCLC Cambridge Science Abstracts (CSA) Ulrich’s Periodicals Directory Summon Serials Solutions ProQuest

Subscription Information: $520/year (print) $360/year (online) $680/year (print and online)

David Publishing Company 3592 Rosemead Blvd #220, Rosemead, CA 91770, USA Tel: 1-323-984-7526, 323-410-1082 Fax: 1-323-984-7374, 323-908-0457 E-mail: [email protected]; [email protected]; [email protected].

David Publishing Companywww.davidpublishing.com

DAVID PUBLISHING

D

Journal of Civil Engineering and Architecture

Volume 7, Number 10, October 2013 (Serial Number 71)

Contents

Housing and Urban Design

1189 Prices of Apartments in Relation to Noise Level in Poland

Kinga Szopińska and Małgorzata Krajewska

1196 Historicity: Preservation or Revitalization Planning Tools?

Mariana Seara Paixão, António Ricardo da Costa and Jorge Gonçalves

1203 Study on Emphases and Trend of Tianjin Urban Public Safety Planning from the View of Bohai

Rim Megalopolis

Gong Yuan, Xiao Yu and Lu Li

1209 Improving Conviviality in Public Places: The Case of Naples, Italy

Gabriella Esposito de Vita, Carmelina Bevilacqua and Claudia Trillo

1220 Design Drivers for Affordable and Sustainable Housing in Developing Countries

John Bruen, Karim Hadjri and Jason von Meding

1229 Investigation of Bed Joint Reinforcement Influence on Mechanical Properties of Masonry under

Compression

Lukasz Drobiec

1240 Evaluating the Effectiveness of Best Management Practices in Gilgel Gibe Basin

Watershed—Ethiopia

Tamene Adugna Demissie, Fokke Saathoff, Yilma Seleshi and Alemayehu Gebissa

Geotechnical Engineering

1253 Performance of a Nonwoven Geotextile Reinforced Wall with Unsaturated Fine Backfill Soil

Fernando Henrique Martins Portelinha, Benedito de Souza Bueno and Jorge Gabriel Zornberg

1260 Models and Optimization of Rice Husk Ash-Clay Soil Stabilization

Iloeje Amechi Francis and Aniago Venantus

Geodesy Applications

1267 Gully Erosion Study and Control: A Case Study of Queen Ede Gully in Benin City

Jacob O. Ehiorobo and Roland O. Ogirigbo

1279 Analysis of the Antenna’s Setup Errors at the Global Navigation Satellite System Measurements

Evangelia Lambrou

1287 Evaluating Land Surface Changes of Makassar City Using DInSAR and Landsat Thematic

Mapper Images

Ilham Alimuddin, Luhur Bayuaji, Rohaya Langkoke, Josaphat Tetuko Sri Sumantyo and Hiroaki Kuze

Architectural Design and Related Analysis

1295 The Industrial Heritage and the New Architecture: Teaching, Researching, Designing the Place

Identity

Monica Bruzzone and Roberta Borghi

1301 Surface Soil Effects Studies Based on H/V Ratios of Microtremors at Kingston Metropolitan Area,

Jamaica

Walter Salazar, Lyndon Brown and Garth Mannette

1323 The Idea of “Architecture Stage”: A Non-material Architecture Theory

Yuke Ardhiati

Oct. 2013, Volume 7, No. 10 (Serial No. 71), pp. 1189-1195 Journal of Civil Engineering and Architecture, ISSN 1934-7359, USA

Prices of Apartments in Relation to Noise Level in

Poland

Kinga Szopińska and Małgorzata Krajewska

Department of Geomatics, Geodesy and Spatial Economy, University of Technology and Life Sciences, Bydgoszcz 85-225, Poland

Abstract: Acoustic climate of a given area ought to be a factor of considerable significance in investment processes in an urbanized area, especially in a residential real estate market, due to its extensive influence on the living standards of its inhabitants. In the following article, the authors have given an analysis of the residential market of housing units located in areas of acceptable and excessive noise levels in preselected regions of Poland. With this end in view, an entirely new source of information has been used in the research—an acoustic map which has been defined and applied to produce the outcome of the analysis. It allowed for the recognition of whether or not the noise level influences decisions made by investors existing in a local residential real estate market.

Key words: Acoustic climate, noise strategic map, residential real estate.

1. Introduction

Noise is defined as any undesirable, disturbing and

harmful sounds causing environmental discomfort.

Produced by sources of various kinds, it contributes to

the creation of acoustic climate of the environment, in

other words an assembly of acoustic phenomena in a

given area [1]. Noise sensitivity is a subjective term

depends upon predispositions of a person as well as

sound characteristics. Thus, certain sounds may in the

same time cause pleasant sensations or be disturbing

depending on a recipient. Acoustic climate existing in

a given area should be a major factor taken into

consideration in an investment process of an

urbanized area due to its significant contribution to

inhabitants’ quality of life, especially regarding

residential real estate [2].

Residential properties, as goods satisfying basic

needs of a man (such as sleeping, eating, relaxation,

family life, studying, housework etc.), have been

categorized in Poland into: detached houses,

semi-detached and terraced houses, tenement houses,

Corresponding author: Kinga Szopińska, Ph.D. student,

research fields: environment engineering, real estate management and protection of urban areas from noise. E-mail: [email protected].

apartments in residential buildings (including

commercial and residential premises as well as

cooperative member’s ownership right for residential

premises) [3]. Residential real estate in Poland is a

consumer market (consumers buy for themselves) to

the greater extend and only relatively small part of it

is an investment market (apartments for rent) [4-6],

which would particularly indicate a significant role of

environmental factors while making investment

decisions. Due to the fact that housing resources

mainly consist of multi-family residential

buildings—approximately 67% [7] apartment market

which is regarded the most developed one, was the

subject of the analysis.

Assuming that transaction prices of properties

reflect their characteristics, an attempt to answer the

question whether the acoustic climate of the

surroundings of a selected research area of Poland

influences the residential real estate market has been

made. The second objective of this paper is to present

the extensive use of acoustic maps not only to

evaluate the noise level but also as a base for

comparative analysis. Therefore the spatial analyses

were performed with the use of NSM (noise strategic

map), the latest (the first acoustic maps in Poland

DAVID PUBLISHING

D

Prices of Apartments in Relation to Noise Level in Poland

1190

were created in the years 2005-2006), professional

source of information concerning the surrounding

space.

2. Acoustic Map

Directive 2002/49/EC of the European Parliament

and of the Council of 25 June 2002 relating to the

assessment and management of environmental is the

major legal act regulating the problem of noise

protection which aims at unifying procedures related

to estimating the level of environment’s exposure to

noise within the member states. According to the

directive, NSM is an averaged map of noise generated

into environment by various groups of sources, which

enables holistic evaluation of a level of noise exposure

within an urban area, provides the possibility to

determine the origins of such phenomena as well as

the opportunity to prepare general prognoses of

alterations of its levels. It is the responsibility of state

members of European Community to restrict the level

of noise in the areas where its harmful influence might

affect inhabitants and to protect areas of appropriate

acoustic climate. Poland, as a member of European

Community is obliged to comply with its law

regulations, including the above-cited directive.

The primary legal act that regulates the noise

exposure safety issues in Poland is the Environmental

Protection Act. According to Article 112, noise

exposure protection means providing the most proper

condition of acoustic climate by maintaining the level

of noise which does not exceed admissible values

defined by LDWN and LN indicators [8]. The

permissible environmental noise level depends on the

nature of its source as well as a purpose of the affected

area. The values oscillate in the range between 40-60

dB (decibel (dB) is a measure of sound pressure level

[9]).

NSM consists of a descriptive and graphical part.

The first one includes characteristics of an area,

acoustic predispositions on the basis of planning

documentation of a commune, identification and

specification of noise sources as well as diagnosis of

endangered areas. The graphical part consists of maps

presenting acoustic climate of a study area. They

include immission maps, acoustic conflict maps as

well as level indicators of inhabitants over normative

noise exposure.

According to Art. 7 of Directive 2002/49/EC

member states were obliged to compile strategic maps

reflecting the situation in the preceding year for all

their agglomerations including statements of the

period of completion: until June 30, 2007—for

agglomerations exceeding 250 thousand inhabitants,

until June 30, 2012—for all the agglomeration within

their territory.

In the view of the directive “agglomeration” is

defined as a territory with the number of inhabitants

over 100 thousand and population density allowing

for being recognized as an urban area by a Member

State.

In Polish Legal System, this notation is supported

by Art. 117 of Environmental Protection Law.

According to the article, the diagnosis of the condition

of acoustic environment is performed within the

national environment monitoring program, on the

basis of the results of noise measurement tests for

agglomerations of above 100 thousand inhabitants.

NSMs have been developed for all the major cities of

Poland which exceed 250 thousand inhabitants

including: Warsaw, Krakow, Szczecin, Wroclaw,

Poznan, Olsztyn or Bydgoszcz. Currently SMAs are

being developed for local governments of

agglomeration of 100 thousand inhabitants [10].

3. Apartment Market Analysis Considering Noise Level

In the present article, it has been stated that

participants of local real estate market take into

account noise level affecting the neighborhood while

making investment decisions such as purchasing an

apartment. Verification of this notion will be carried

out considering a preselected region of Poland, based


1191

on a spatial analysis of transaction prices of housing

units in relation to an existing noise level defined by

NSM.

3.1 Research Area Characteristics

The researched market is residential real estate

segment of housing units being a subject to real

property ownership rights. The research area is

located in the city of Bydgoszcz, one of the vastest

settlement centers of Poland, located in the northern

part of the country. The city is situated on the banks of

the Brda River and Bydgoszcz Canal, whose eastern

part borders the Vistula River. The research involves

several districts: Akademickie-Wschod, Przylesie,

Bohaterow and Bajka covering the area of 458 ha

(hektar is a unit of measurement of land area) in

Fordon, an administrative unit of Bydgoszcz (Fig. 1).

The multi-family residential function is

predominant in this area which dates back to one

period of history—the 80-ies of 20th century.

Service-oriented structures of basic functionality

provides complimentary function of the area. Road

access is provided by the streets listed in Table 1.

Noise generated by engine vehicle traffic in the

streets creates higher noise zones which significantly

affect the surrounding area [11]. The size of the

emission, as well as the transgressions, depend on

traffic level and in the same time, the following road

parameters: type and condition of the surface, number

of lanes and their direction, existing traffic lights as

well as speed limits for cars and trucks [2].

The period of prices examination included the

period of 2009-2010 that is the time following the

price correction on the apartment market in Poland,

the post-crisis times after which market prices

stabilization emerged [4, 12, 13]. It allowed for

restraining from making corrections on the basis of

price level changes caused by time lapse (time trend

equal to 1.0).

Fig. 1 Polish map of selected cities from the developed SNM.

Table 1 Main streets characteristics in a given area.

No. Street name Road category Road type Surface type Surface condition* Speed limit (km/h)

1 Fordonska National Main

Asphalt of good condition

a 80, 50 2 al. Prof. S. Kaliskiego Local Service a 50 3 Akademicka District Main b 50 4 Jana Brzechwy Local Service m 50 5 gen. Władysława Andersa District Main b 50 6 Igrzyskowa Local Other o 30 7 Christiana Andersena Local Other m 50 8 Wojciecha Korfantego Prejsa Local Service m 50 9 Jozefa Twardzickiego Local Service m 50 *m—medium, a—alerting, b—bad, o—other.


1192

3.2 Market Analysis in Spatial Context

For the previously defined nature and area of the

market as well as the period of prices researching,

information of 146 residential unit transactions were

gathered. Defined average prices of apartments in the

buildings in which the transaction occurred. The study

included 45 of the buildings, which accounted for

36.6% of all residential buildings in the analyzed area.

Average prices were placed between 2,541.30 zł/m2 ÷

4,110.68 zł/m2 of useable floor area (złoty is the basic

unit of currency in Poland). In the subsequent stage,

average prices of apartments in the buildings have

been grouped according to the following price ranges:

(1) those of average prices placed in the range up to

3,000 zł/m2 of useable floor area;

(2) those of average prices placed in the range from

3,000 zł/m2 to 3,500 zł/m2 of useable floor area;

(3) those of average prices placed in the range

exceeding 3,500 zł/m2 of useable floor area.

The price ranges included apartment transactions of

the same general location, same utilities similar

transport accessibility, similar technical condition of

buildings and the same management system. They

varied in size (total floor area ranged from 30.73 m2 to

78.86 m2) finishing standards, floor level as well as

detailed location, which as a property feature, includes

noise level generated by engine vehicles.

While attempting to find the answer to the question

whether noise influences apartment prices, data

concerning very similar properties was gathered with

the use of ceteris paribus principle (which means

unchanged remaining circumstances), and varying

only in terms of one feature which is their detailed

location, including noise level factor. The technique

allows for researching highly complex problems with

the sacrifice of some realism [14]. Unfortunately, it

was apparently impossible to eliminate every

distinguishing feature of the apartments in the course

of the study, especially those individual ones

concerning the finishing standards, total floor area or

floor level. Therefore, it has been assumed that

introducing three price ranges including similar

properties, only varying in some individual qualities,

into the analysis will greatly decrease the influence of

these attributes on the value, thus detailed location

will remain the only distinguishing feature. Such an

analysis policy has been acknowledged right, since the

purpose of the research was not the pursuit of the

Fig. 2 Prices of single transactions in relation to noise factor of the neighborhood [15].

4,000

3,500

3,000

2,500

Pri

ce o

f ra

nge

(zł/m

2 p uz)


1193

Table 2 Number of transactions in price ranges depending on meeting acoustic standards by resident areas [15].

No. Kind of area Number of transactions in price ranges

Below 3,000 zł/m2 useable floor area

3,000 ÷ 3,500 zł/m2 useable floor area

Above 3,500 zł/m2

useable floor area 1 For the analyzed area 6 68 72

2 Residential areas meeting acoustic standards (level of noise does not exceed 55 dB)

1 47 70

3 Residential areas which do not meet acoustic standards (exceeded levels of noise over 55 dB)

5 21 2

Fig. 3 Spatial location of appartment transactions in relation to a map of excess road traffic noise LDWN (Przylesie, Bohaterow, Akademickie-Wschod districts).

Fig. 4 Spatial location of appartment transactions in relation to a map of excess road traffic noise LDWN (Bajka district).

< 3,000 zł/m2puz 3,000 ÷3,500 zł/m2puz >3,500 zł/m2puz

< 3,000 zł/m2puz 3,000 ÷ 3,500 zł/m2puz > 3,500 zł/m2puz


1194

importance of noise level as a feature but the question

whether, being an environmental condition, it

influences the decision making process of market

participants.

The number of transactions in single price range

has been presented in Fig. 2 and Table 2 and their

spatial orientation, with the division into districts in

Figs. 3 and 4. The information originating from the

real estate marked was presented in relation to an

extract of a strategic acoustic map of the city of

Bydgoszcz. In Poland for the multi-family housing

properties accepted road traffic noise level must not

excess 55 dB [9].

4. Conclusions

The analysis allows for drawing the following

conclusions:

(1) Acoustic map is certainly a helpful in the

analysis and credible source of information

concerning noise levels. According to European

Union Directive 2002/49/EC, it is available in

numerous Polish agglomeration or it will appear in a

near future;

(2) Most of multi-family residential buildings in the

area of the study in Poland—the districts of Fordon in

the city of Bydgoszcz is located outside the zone of

excessive traffic noise levels;

(3) Out of 118 market transactions concerning sales

of apartments located in buildings of acceptable noise

level areas, most of them (60%) originated from the

range of the highest price values: > 3,500 zł/m2 of

useable floor area and only 1 transaction from the

lowest value range below 3,000 zł/m2 of useable floor

area. The remaining, approximately 30%, came from

the range of 3,000 ÷ 3,500 zł/m2 of total floor area;

(4) Out of 28 transactions of apartments situated in

buildings of excessive noise level, a majority of them

(75%) obtained lower price level of 3,000 ÷ 3,500

zł/m2 of total floor area and 18% of those—the

lowest—below 3,000 zł/m2 of total floor area. Only

two of them obtained the highest level;

(5) Preliminary research results have shown that

real estate market participants take unfavorable

acoustic climate of the surrounding area into

consideration while purchasing residential properties,

which results in lower price of a given apartment;

(6) Unfavorable environment interaction such as

noise is reflected in lower market prices paid for

residential properties located in areas of excessive

noise level.

The preliminary results can be further validated

using statistical methods such as multiple regression

analysis [16].

References

[1] J. Kwiecień, K. Szopińska, Implementation of the EU noise directive in process of urban planning in Poland, international archives of the photogrammetry, remote sensing and spatial information sciences, in: 29th Urban Data Management Symposium, London, United Kingdom, May 29-31, 2013.

[2] J. Kwiecień, K. Szopińska, M. Sztubecka, Problem of noise protection in urban areas on the example of Bydgoszcz, Ecology and Technology 18 (4) (2010) 205-212.

[3] M. Krajewska, Planning conditions and the market value of real estate, in: E. Siemińska (Ed.), Investment on the Real Estate Market, Scientific Publisher of Nicolaus Copernicus University, Toruń, 2011, pp. 63-99.

[4] Analysis of the Housing Market, 2011, http://www.rp.pl/temat/230927.html (assessed Sep. 1, 2012).

[5] Appraisal Institute, The Appraisal of Real Estate, 11th ed., Chicago, Illinois, 1996.

[6] L. Nykiel, The functions and role of the state in the housing market, Journal of the Polish Real Estate Scientific Society 18 (3) (2010) 7-21.

[7] M. Rymarzak, Housing Market in Selected EU Countries, Real Estate—Valuation, Profitability and Risk, Papers and Reports of the Faculty of Management of Gdansk University, Sopot, 2000, pp. 167-174.

[8] M. Krajewska, K. Szopińska, The acoustic map as a source of information about the real estates, World of Real Estate 76 (2011) 29-33.

[9] Z. Engel, Environmental Protection against Vibration and Noise, Polish Scientific Publishers PWN, Poland, 2001.

[10] Noise Map of City of Bydgoszcz, Bydgoszcz, 2008, http://mapy.bydgoszcz.pl/bydgoszcz/index.php/en/ (assessed Sep. 1, 2012).


1195

[11] C. Asensio, J. López, R. Pagán, I. Pavón, M. Ausejo, GPS-based speed collection method for road traffic noise mapping, Transportation Res. Part D: Transport and Environment 14 (5) (2009) 360-366.

[12] E. Siemińska, Residential buildings developers functioning in Poland after the crisis, Journal of the Polish Real Estate Scientific Society 18 (3) (2010) 29.

[13] E. Siemińska, Banks’ practical experience in shaping credit policies for financing the real estate market, in: E. Siemińska (Ed.), Investment on the Real Estate Market, Scientific Publisher of Nicolaus Copernicus University,

Toruń, 2011, pp. 32-42. [14] E. Kucharska-Stasiak, Back to the sources—Discussion

about the market value, Valuer 67 (2010) 16-22. [15] M. Krajewska, K. Szopińska, The acoustic climate as a

factor affecting the market value of real estate of housing, in: 3rd International Seminar on Urban Investments, Cracow, 2011, pp. 447-455.

[16] R. Cellmer, Spatial analysis of the effect of noise on the prices and value of residential real estates, Geomatics and Environmental Engineering Selected Full Texts 5 (4) (2011) 13-28.


Historicity: Preservation or Revitalization Planning

Tools?

Mariana Seara Paixão, António Ricardo da Costa and Jorge Gonçalves

Instituto Superior Técnico, Universidade Técnica de Lisboa, Lisboa 1049-001, Portugal

Abstract: The historic centres revitalization addresses the challenges related to the preservation of fundamental heritage values. At a time, when everyone looks with concern to our cities’ future, it is important to reflect on the received heritage, seeking the most appropriate answers to the planning of the historic centres. These fabrics are reference places in the urban space, due to their role of memorial testimony and of generators of cultural and economic dynamics. However, often times, inherited urban fabrics are affected by the limitations of the heritage policies which, for being too general and based on theoretical and abstract frameworks, have difficulty incorporating the characteristics of each area and neglect the formulation of specific criteria and intervention methods. The purpose of this paper is to provide a comparative reading of the levels of urban renewal allowed by the planning tools. This study chooses two historic centers in Portugal: Oporto and Guimarães historic centres (World Heritage Sites since 1996 and 2001, respectively, and were the last to get this classification in Portugal). This reflection is a contribution to peer trends and raise the discussion on the role that the different heritage policies have to the revitalization of the historic centres. Key words: Historical centre, planning tool, urban renewal, heritage, urban planning.

1. Introduction

Cities are concentrating their worries on territory

qualifications and the central territories have seen

their role reinforced on the social and economical

development promotion of themselves. It is urgent to

tackle the challenges related to the safeguard of

heritage fundamental values along with the need for

revitalization of historic centres, giving them new

functionalities and residential attractions.

Consequently, it is important that pre-existence

management policies are capable of their preservation

and at the same time adequate for present and future

challenges. Heritage policies dictated by current

planning tools represent the conservation strategy

adopted by each historic centre. We will be looking to

evaluate the different policies adopted for this heritage

preservation, especially concerning its adaptability

capacity for a sustainable future.

Corresponding author: Mariana Seara Paixão, master,

research field: urban morphology. E-mail: [email protected].

2. Historic Centres: Conceptual Evolution and Heritage Policies

2.1 Concept Developed up to 1st World War

The urban heritage concept has changed with time

in its articulation with the historic centres, in

accordance with the social perception of the value of

this resource. Urban renovation policies adjusted to its

own heritage evolution in accordance with its

respective era, social characteristics, culture,

economics and policies. In this evolution, we can

emphasize three distinctive phases of urban

renovation policies: preservation, conservation and

heritage [1]. Preservation was the first phase for these

policies and focuses on buildings looked upon as

monuments, selected by beauty or age criteria. The

constructions were preserved by legal protection rules

imposed by specialists, whom identified its relevance

as cultural goods [2].

2.2 Concept Developed between World Wars

The 20th century modern movement upholds a

DAVID PUBLISHING

D

Historicity: Preservation or Revitalization Planning Tools?

1197

radical approach for the intervention and resolution of

historic centre’s problems. The modern movement

supported the destruction and reconstruction

according to modern principles, not giving especial

importance to the pre-existences, as exemplified by

the Voisin Plan (1925) conceived for Paris by Le

Corbusier.

However, at the same time, radically opposed

concepts started to emerge to this approach of looking

at the inherited city. We underline the works of

Gustavo Giovannoni—for whom the historic city was

a monument, because of its topography, landscape

character and the set of built typologies.

It is after the 1st world war that the intervention in

historic centres considerations intensify, because a fast

answer became imperative for the rebuilding of the

destroyed cities. The Italian Giovannoni gave an

important contribution, for this reflection, in

formulating the urban heritage concept, considering

the historical city as a density of relevant values. We

underline the works of Gustavo Guiovanni who

developed the minor architecture concept meaning a

monument conception viewed not anymore as an

isolated spatial piece, but with an essential

surrounding for its understanding [3]: one asset that

should be preserved through protection laws as it

already existed for isolated monuments [4].

2.3 Concept Developed after the 2nd World War

It is only in the sixties, a strong economical

recuperation period after the 2nd world war, that

renovation methodologies in historical centres were

implemented for the first time in Europe, such as the

Plan de Sauvegarde et Mise en Valeur do Marais

(1969) in Paris, and Bolonha’s Historical Centre

Regulating Plan [5]. These places were degraded

physically and at a social, cultural and economic level,

enabling the change for a second phase of urban

conservation policies, the conservation, magnifying

the attention aimed at urban sets [2]. At this stage, the

goal was to better the physical environment, such as

housing, and at the same time, solve the social

problems of the resident population.

Nowadays when everybody anxiously looks with

concern to the city’s future, it is important to reflect

over the received heritage of the past, in order to

search for the most adequate answers for planning and

managing of the historic centres in the set of the

contemporary city.

The international orientations mirror the worries

and distinctive attitudes towards the preservation and

conservation of historic centres as a resource and

legacy for future generations. General heritage

safeguard international documents show us a diversity

of conceptual evolution that justified the intervention

in these places, like as the role of contemporary

architecture and urban planning.

Five relevant international documents can be

identified:

(1) Nairobi’s Recommendation (UNESCO, 1976)

determines that the historical set and its surrounding

are a coherent whole, but identifies new constructions

as a threat that could destroy the set’s character

(consulted in Ref. [6]);

(2) Resolution 813 (Council of Europe, 1983)

assumes as a guide rule the need to integrate

contemporary constructions in historic sets, in order to

give continuity to the architectural tradition and

building a future European heritage (consulted in Ref.

[5]);

(3) Washington’s Charter (ICOMOS, 1987)

identifies as a guide rule that the historical sets

safeguard should be carried out through social and

economical coherent development policies. It supports

the preservation of urban forms, of the built and

empty spaces relationship, building’s form and

function (consulted in Ref. [6]);

(4) Burra’s Charter (ICOMOS [7]) for the first time

identifies a larger conservation concept,

“Conservation means all the processes of looking after

a place so as to retain its cultural significance” (Art.

1.4) which “means aesthetic, historic, scientific, social

or spiritual value for past, present or future

generations.” (Art. 1.2);


1198

(5) Vienna’s Memorandum (UNESCO [8])

identifies as guideline the acceptance of the city’s

building process, in which change plays an integrated

part. It defends heritage conservation and

simultaneously its modernization strengthening its

own identity and social cohesion. Hence,

contemporary architecture should complement the

existing urban historical landscape as a fundamental

strategy.

Historical centres today are treated by the third

phase of urban renovation policies, the heritage, which

occurred when they came under a market orientation

[1]. The architectural legacy began to be seen as a

consumer selected product, and managed by current

market demands. The past is molded to answer

contemporary needs [9]. It has become an urgent

necessity that conservation and urban planning have a

symbiotic relationship that leads to harmonious cities

development [10].

Historic centres carry a double achievement of

being a memorial witness, as well as a generator of

cultural, economic and social dynamics, crucial for the

cohesion and qualification of the contemporary city.

Therefore, historic centres are reference places in the

urban space.

However, the urban net legacy is many times

penalized by the heritage policies limitations that, by

being too general and established by theoretical tables,

have difficulty in incorporating each intervention

area’s singularities. Usually heritage policies do not

care for the formulation of criteria and methodologies

adjusted and adapted for each case.

Planning in historical sites resides nowadays in the

dictum between preserving the past, by its intrinsic

value, and the transformation necessity, answering to

the values of a restless for innovation, inclusion and

culture seeking society. As such, if urban areas do not

have the ability to change, they will end up stagnating

in the set of the urban fabric [11].

“Conservation is a complex process of managing

the tensions between continuity and change in the city,

and its main aim is to manage the cultural character

and identity of the city” [12].

3. Evaluation of Clearness and Renovation Capacity of Planning Instruments in Emblematic Portuguese Historical Centres

When the planning instruments have explicit rules,

it minimizes the bureaucracy and maximizes the

margin of interest in the projects, thus boosting

economies, population flows, services and cultural

programs to these historic centers through a clear and

objective management of urban renewal. This can

result in a gradual and rigorous transformation of the

built fabric that leads to the preservation,

revitalization and sustainable development of this

urban heritage.

The following analysis focus on two historic

centres in Portugal: Oporto and Guimarães historic

centres, which are World Heritage Site since 1996 and

2001, respectively. These two historic centers were

the last to get this classification, of the four existing

World Heritage historic centers in Portugal.

The current planning and management instruments

for these historic centres reflect different ways of

thinking and intervention on built heritage enabling us

to understand the different policies adopted for the

conservation and renewal of these world heritage

urban places.

3.1 Guimarães Historic Centre

3.1.1 Plan Type and Management Entity

In the historic centre of Guimarães the Local

Technical Office (GTL (Gabinete Técnico Local)) is

the responsible entity for managing the interventions

in buildings (Fig. 1). This entity has a threefold

objective of maintaining the population, provide better

living conditions and preserve/restore the heritage

values of authenticity. The GTL advocates a logical

maintenance and minimal impact through the use of

skilled local labor, materials and traditional

techniques.


1199

Fig. 1 Plan with the delimitation of Guimarães historic centre classified as World Heritage (in blue) and its protection zone (in red) [14].

3.1.2 Criteria and Levels of Intervention

The Local Technical Office classifies interventions

according to two categories: light works and deep

works. Light works focus on repairing facades, eaves,

window frames, painting elevations or introduction of

sanitary facilities. Deep works include interventions in

the structure and interior organization.

This entity elaborated the Regulation for

Intervention in the Urban Center and History of

Guimarães (RICUH, 1994), which requires multiple

constraints for urban renewal. It constrains exterior

characteristics, as facades design, colors and materials,

these should be maintained as the originals. In

buildings interior the same method is applied, original

typology and materials should be also preserved.

3.2 Oporto Historic Centre

3.2.1 Plan Type and Management Entity

In Oporto’s historic centre, the built heritage

intervention management is run by Porto Vivo—SRU

(Urban Rehabilitation Society) [13], whom since 2004

produced Strategic Documents for each block,

assuming each of these as an intervention unit (Fig. 2).

These strategic documents establish the foreseen and

authorized works in each building, safeguarding the

minimum sanitarian and habitability conditions.

The strategic documents have law enforcement

power over the building and has to be followed both

by public and private dwellers. The foreseen

interventions were produced by the joint work of

Porto Vivo—SRU with the Portuguese Institute for

Management of Architectural and Archaeological

Heritage (IGESPAR—Instituto de Gestão do

Património Arquitectónico e Arqueológico).

3.2.2 Criteria and Levels of Intervention

Porto Vivo—SRU’s strategy covers an extended

range of concerns placed both on the survey and

diagnosis of the existing conditions and in the

procedures for the intervention management (Table 1).

The Porto Vivo—SRU, with a deep knowledge of

its intervention area and in order to clarify its

intervention criteria in the historic centre buildings,

has also established three building intervention

categories: light, medium and deep. A light intervention

is applied in buildings in a reasonable conservation

state and the intervention can not interfere with the daily

Fig. 2 Plan with the delimitation of Porto historic centre classified as World Heritage (in pink) and its protection zone (in yellow) [15].


1200

Table 1 Intervention criteria in Oporto’s historic centre.

1. Intervention technological aspects

-Understanding and respecting the existing building, the primitive technologies, and if not possible assuring that new technologies are compatible with the old ones.

2. Urban Elevations -Maintaining and qualifying elevations, through consolidating operations; -Repairing and cleaning (reposition of original elements by withdrawing unfitting elements).

3. General typological resolution

-In profound or deep interventions, to maintain the elevations, and main building side walls, in order to maintain relationship between external openings and internal spaces; -In deep interventions there are typological reformulation operations, in the scope of plot definition, internal spatial room alteration, horizontal and vertical distribution common areas alteration, with the introduction of lifts, equipments and services demanded by current legislation.

4. General criteria for technical interventions

Aims to any level of intervention: -Respect as much as possible for building’s insertion environment; -General rehabilitation and anomalies correction, focus on structural safety and fire risk; -To abide current demands for new construction whenever possible; -Primitive elements upgrading, with authenticity, safeguarding their compatibility with new intervention elements.

5. Securing of main demands

(a) Structural safety: -Introducing new structures (concrete, metal or steel) to reinforce the building main structure and creation of new vertical communications; -Traditional timber structures ( ensure fire safety, acoustic insulation and waterproofing in water areas); -To reinforce foundations and seismic resistance. (b) Safety against fire risk: -Risk reduction measures of fire starters and fire spreading. (c) Hygrometric thermal comfort: -(New construction or deep intervention) uphold thermal comfort passive systems , to reduce heating thermal charge, through good insulation and minimize cooling active systems (air conditioning); -(Existing construction rehabilitation or light interventions) reinforce roof thermal insulation, renewal of degraded opening’s frames (thermal bridges); -Insulation reinforcement (roof, opening frames, double glazing, lowering thermal bridges, bettering night ventilation systems). (d) Acoustical comfort: -(New or deep constructions) fulfillment of current demands; -(Existing constructions), sound insulation between storeys (ceilings and/or roofs) and between plots, reinforcement and insulation of opening frames. (e) Healthcare of conveniences and kitchens: -Employment of ventilation, water supply and drainage, necessary equipment and washable, waterproof and resistant finishes. (f) Services and infra-structures: -Application of rainwater drainage, telecommunications, active security and gas systems. (g) Durability and economics: -Pragmatic attitude in solutions choices, as to cost and acceptable durability, through control and critical continuous assistance in all project phases.

Source: Ponte Nova, PBDE, Annexe II.

life of the residents. The medium intervention

concerns the repair of timber works and opening

frames, reinforcement of some structural elements, as

floors, roofs and walls. It also includes the

improvement of the commons parts of the buildings

and upgrading functional conditions in accordance to

current legislation. The deep intervention mainly

includes light and medium interventions and it is also

about changing the typological organization (number

of plots, functions). It implies demolition and

reconstruction, it also allows changing materials and

finishes and can imply temporary relocation of the

building residents.

4. Conclusions

This reflection is a contribution not only to interpret

the effects of the different planning tools in the

architectural interventions in historic centers, but also

to peer results and trends. Thus it raises the discussion

about the role that these different policies assume

through the planning tools to the urban conservation

and renewal, i.e., in the revitalization of the historic


1201

centres, which possess strong identity valences.

Comparatively, we can see that the planning tools

that allow greater urban renewal are the Strategic

Documents in Oporto. In this historic centre, the

strategy developed by Porto Vivo—SRU is based on

the deep knowledge of the buildings, preserving its

original design and aesthetic from the exterior, but

allowing contemporary interventions that benefit the

whole. The strategy followed by Porto Vivo—SRU

allows a deeper intervention inside the buildings, with

the aim to provide the standard conditions of

habitability for contemporary people that want to live

in these places without losing comfort.

In Guimarães the RICUH, designed by the Local

Technical Office, reflects a reduced possibility of

intervention with contemporary values in this historic

centre. Almost all characteristics must remain as the

original features of the buildings, either exterior or

interior. In our interpretation, this shows a strategy of

perpetuating the past values, believing that

contemporary architectural values would reduce the

artistic, social, cultural values and the economic

development acquired by the place so far.

Although in both cases different levels for

intervention are set (Oporto—light intervention,

medium intervention, deep interventiona and

Guimarães—light works and deep works), the planning

instruments establish clearly different approaches to

deal with the urban renewal of the built heritage.

In sum, we can understand that the latest

Portuguese planning tools, and the Strategic

Documents in Oporto, are the most complete and

flexible. They cover, for example, how to intervene on

the building’s structural system and they also point

out objectively the constraints relating to the factors of

facade design, roof and internal typology. This

planning approach, through strategic documents,

allows a regulated change of the historic centre. On

the other hand, the approach developed for Guimarães

historic centre defends quite the opposite, it supports

the idea of maintenance of the past as it, not adding

contemporary values.

As suggested by the Vienna Memorandum [8] in

the management of architectural interventions in the

historic centres must exist as a principle the

acceptance of change as part of the construction of the

city, not only advocating the preservation of heritage,

but also and at the same time, the upgrading in order

to strengthen the identity and social cohesion. The

planning tools of Oporto, and the Strategic Documents,

are the ones studied that best embody the idea of

preservation and revitalization support by the Vienna

Memorandum, which is necessary to keep the historic

centres actual and alive in the contemporary city.

References

[1] G.J. Ashworth, From History to Heritage—From Heritage to Identity: In Search of Concepts and Models, Building a New Heritage, Tourism, Culture and Identity in the New Europe, Routledge, London, 1994, pp. 13-30.

[2] S. Tiesdel, T. Oc, T. Heath, Revitalizing Historic Urban Quarters, Architectural Press, Oxford, 1996.

[3] F. Choay, Consulted Version, The Allegory of Heritage, Edições 70, Lisboa, 2008. (in French)

[4] J. Aguiar, Some brief notes on the history of urban renewal, in: The Conference of Challenges and Proposals for an Application for World Heritage, Universidade de Coimbra, Coimbra, 2007. (in Portuguese)

[5] A.M. Tung, Preserving the World’s Great Cities, The Destruction and Renewal of the Historic Metropolis, Clarkson Potter, New York, 2001.

[6] F. Lopes, M.B. Correia, Architectural and Archaeological Heritage-Charts, International Conventions and Recommendations, Livros Horizonte, Lisboa, 2004. (in Portuguese)

[7] ICOMOS, The Burra Charter, Australia, 1999, http:// australia.icomos.org/publications/charters/ (accessed May 24, 2011).

[8] UNESCO, Memorandum de Viena aquando da Conferência Internacional “Património Mundial e Arquitectura Contemporânea—Gestão das Paisagens Urbanas Históricas”, 2005, http://whc.unesco.org/archive/ 2005/whc05-15ga-inf7e.doc (accessed May 30, 2011).

[9] N. Nasser, Planning for urban heritage places: Reconciling conservation, tourism and sustainable development, Journal of Planning Literature 17 (2003) 467-479.

[10] N. Cohen, Urban Planning, Conservation and


1202

Preservation, McGraw-Hill, New York, 2001. [11] P. Larkham, Conservation and the City, Routledge,

London, 1996. [12] W.K. Liu, Managing change: Tensions between urban

morphology and everyday life in the heterotopic urban content of Tainan, Ph.D. Thesis, University of Edinburgh, UK, 2011.

[13] Porto Vivo—SRU, PBDE (Plano Base do Documento

Estratégico) Ponte Nova, 2006, http://www.portovivosru.pt/ (accessed Apr. 14, 2011).

[14] Câmara Municipal de Guimarães, Gabinete Técnico Local, Regulamento de Intervenção no Centro Urbano e Histórico de Guimarães [online], 1994, http://www.cm-guimaraes.pt/ (accessed May17, 2011).

[15] IGESPAR Homepage, www.igespar.pt (accessed Apr. 4, 2011).


Study on Emphases and Trend of Tianjin Urban Public

Safety Planning from the View of Bohai Rim Megalopolis

Gong Yuan, Xiao Yu and Lu Li Tianjin Urban Planning and Design Institute, Tianjin 300201, China

Abstract: Nowadays urban public safety has been an important subject of study in urban planning study. And planners realized that a safe city is very important for sustainable development. Traditional urban public safety planning begins to perfect the contents and method. And regional research is an important aspect in the improvement of new era urban public safety planning. This paper chooses Tianjin, the important city in Bohai rim area as the example for research. Tianjin urban public safety planning includes not only comprehensive disaster prevention and reduction, effectively preventing and reducing disasters, ensuring the safety of the life and property of the residents, but also sharing resources and facilities from the view of megalopolis, eliminating hidden area troubles, reducing whole environment risks and so on.

Key words: Urban public safety planning, Tianjin, Bohai rim megalopolis, emphases.

1. Introduction

Nowadays urban public safety has been an

important subject of study in urban planning study.

And planners realized that a safe city is very important

for sustainable development. China government

begins to pay more attention to urban public safety

system and perfect the contents and method of

traditional urban public safety planning.

1.1 Understanding of Urban Public Safety Risk

Sources

Risk sources that pose threats to urban public safety

are classified as natural sources, man-made sources

and other sources with natural and artificial factors.

The public safety emergencies fall into four types

according to the documents issued by China—Master

State Plan for Rapid Response to Public Emergencies

in 2006 and Emergency Response Law of People’s

Republic of China in 2007:

Natural disaster: It covers drought and flood,

meteorological disaster, earthquake, geological

disaster, marine disaster, bio-disaster and forest and

Corresponding author: Gong Yuan, chief planner, research

field: urban planning. E-mail: [email protected].

grassland fire, etc.;

Accident disaster: It covers all kinds of safety

accidents in industrial and mining enterprises, and

trade and business, traffic accidents, public facilities

and equipment accidents, environment pollution and

ecological destruction, etc.;

Public health events: It covers infectious diseases,

mass unexplained diseases, food safety and

occupational hazards, animal epidemic diseases and

other events that will heavily affect people’s health

and life;

Social security: It mainly covers terrorist attacks,

economic safety events and foreign emergencies.

Through matrix analysis of affection and

relationship between urban public safety risk sources

and urban planning, we confirm that all nature disaster,

environment pollution and ecological destruction in

accident disaster, water safety in public health events

and terrorist attacks in social security have the closer

relationship with urban planning, and will be our

research emphasis [1].

1.2 New Task of Urban Public Safety Planning

It is a new task about urban planning and

DAVID PUBLISHING

D

Study on Emphases and Trend of Tianjin Urban Public Safety Planning from the View of Bohai Rim Megalopolis

1204

construction to establish urban public safety system

and emergency management system. To establish the

public safety system of cities and improve the overall

safety of cities, we should take the emergency

management ability and the risks from urban

construction into accounts at first. Therefore, the

research of urban planning would face new challenges

as follows [2]:

• Firstly, the existing traditional system of disaster

prevention and reduction would turn to integrated

safety system of urban public;

• Secondly, we need to conduct the design and

construction of urban planning in terms of the demand

to establish sound social warning mechanism,

emergency mechanism and social mobilization system,

and improve the disposal of emergency and public

safety;

• Thirdly, enhance the integrated and full

management of urban planning. Turn single disaster

management to integrated disaster management and

crisis management, turn the safety prevention of cities

to the full management covering prevention,

emergency response and reconstruction, turn the

operation of a single system to the overall system;

• Fourthly, under the public safety planning

process implement the regional coordination and

urban-rural integration theory, and expand the

perspective and thought in drawing up the public

safety plan.

2. Bohai Rim Megalopolis Development and Tianjin Urban Public Safety Trend

2.1 Bohai Rim Megalopolis Development

The rapid expansion of urban megalopolis have

become an overwhelming space phenomenon in the

era of economic globalization and information, and

the megalopolises all over the world have gradually

become the larger metropolis area and city groups.

Urban megalopolis has also become the main form of

towns in China. Bohai rim megalopolis is entering the

integrated development period of strategy with Pearl

River Delta and Yangtze Delta, which is constituted

by Beijing-Tianjin-Hebei area, Shandong Peninsula

and central-southern Liaoning Province (Fig. 1) [3].

As a channel for northern China to conduct its

opening up, Bohai Zone is the gateway for opening up

to the outside world in the north of China and plays an

important role in connecting the south and the north,

as well as the east and the west, and also in

participating the global economy competition and

cooperation, especially in northeast Asia area. Under

the support of national strategy and policy, it is

necessary and possible to shape up integral and huge

world-class urban megalopolis.

Bohai rim megalopolis research scope including

two municipalities (Beijing and Tianjin) and three

provinces (Liaoning, Hebei and Shandong) with land

area 522,000 km2 and sea area 95,000 km2. Bohai rim

megalopolis has population of 240 million in 2011

which occupy 17.8% of China and GDP of 10.1

trillion RMB in 2010 which occupy 25.3% of China.

Now this megalopolis is in its increasing period and it

is important to establish a comprehensive region

public safety cooperation mechanism as soon as

possible [4].

Fig. 1 Bohai rim megalopolis research scope.


1205

2.2 Tianjin Public Safety Trend from the View of Bohai

Rim Megalopolis

At present, the overall situation of Tianjin public

safety is stable. With an analysis of the disaster

sources due to Tianjin’s geography and climate

environment, geological factors, ecological factors

and the city itself, the potential natural disasters of

Tianjin include drought, flood (including storm tide),

earthquake and other disasters which derived from the

above disasters. Among them, flood (including storm

tide) and earthquake belong to emergency disasters.

The rescue is difficult and it needs to enhance the

prevention of disasters in case of no disasters.

On the other hand, after 9.11 attacks, terrorist

attacks which aim to attack metropolises now have

gradually become the key research of urban public

safety. Bohai rim megalopolis takes the key strategy

as the co-built of world-class cities by Beijing and

Tianjin and focusing on the development of coastal

areas. Tianjin and Beijing would bear responsibilities

for various urban functions of world and own ports

and coastlines at the same time. It is more likely for

Tianjin to face terrorist attacks whether from

perspectives of politics, economy or culture.

Therefore, Tianjin must play a significant role in

maintaining national safety and lifeline system. And

public safety planning of cities based on the

traditional integrated prevention planning of single

city, should establish system from regional

perspective and guide Tianjin to build a safe city

under the new national strategy.

3. Study on Emphases of Tianjin Urban Public Safety Planning from the View of Bohai Rim Megalopolis

3.1 Establishing Ecological System of Regional

Integration

(1) An ecological pattern of regional integration and

pilot projects for ecological compensation have been

conducted in Jixian Mountain, the

“Qilihai-Dahuangpu” marsh and the

“Tuanbo-Beidagang” marsh. It is also an important

part of the security system of ecological safety in

Bohai rim megalopolis (Fig. 2);

(2) We attempt to establish the ecological

compensation mechanism by the Luanhe-Tianjin

water diversion project, and take market method of

compensation such as the transfer of water rights and

paying for the water resources. And we also actively

explore the compensation method of technological

projects, help to develop pollution-free ecological

industries in upper water resources of Hebei by taking

advantages of technology and fund, and finally

achieve the balance between development and

protection. At last, we will explore the safeguard

mechanism for regional public safety;

(3) We should perfect the monitoring and feedback

mechanism of water quality in Haihe River, control

the water quality of trans-boundary rivers, and

collaboratively manage the pollution resources in

villages and cross-regional watercourse. We should

improve the river pollution control by taking Haihe

River as the breakthrough point and protect the

regional water;

(4) We should protect the coastlines of Bohai Gulf,

optimize the coastal industry distribution with policy

and market control, cut the total amount of emissions

in waters and prevent the environment deterioration

and ecology unbalance in coastlines to achieve the

safe use of sea.

3.2 Improving Regional Carrying Capacity of Water

Resources and Environment

Water shortage is the main bottlenecks to restrict

the development of Tianjin and Bohai areas, and the

public safety hazard that Bohai areas would face in the

future. Water shortage would be increasingly

prominent under the city’s rapid development and the

investment of a large number of great and good

projects in high level. Therefore, from the perspective

of regions, we should focus on the development strategy


1206

Fig. 2 Ecological pattern of regional integration.

of Tianjin water resources in urban planning of public

safety. We should vigorously promote the desalination

and take full account of the relations between

development and protection to realize the integrated

development and comprehensive utilization of the

water resources such as surface water (including

transferred water), groundwater, desalinated water and

resurgent water. And in the process, we should

conduct water-saving at first, focus on urban and

rural security of water supply, and take full account

of the carrying capacity of water resources and

environment:

(1) We should make use of the advantages of

seawater desalination in Tianjin, and provide more

water resources for surroundings to alleviate the

widespread water shortage problems in Bohai areas;

(2) Build an industrial chain of

“thermoelectricity-desalination-salt manufacturing

with concentrated seawater—the extraction and use of

chemical resources on seawater”, develop seawater

desalination technology, promote a serious of new

measures and new technology of seawater

desalination in the river estuary, promote the use of

clear energy and recyclable energy to achieve

energy-saving goals and reduce the impact of

desalination on ecological environment;


1207

(3) Under the development of the non-traditional

water resources such as recyclable water and seawater,

we would further enhance and perfect the use and

management of traditional water resources, and

increasingly support the Tianjin water resources by

inter-basin water transfer project.

3.3 Improving Regional Sharing and Linkable Traffic

and Communications Network

In the planning, we establish high level traffic and

communications network in the city, from city to city

and from region to region and create various methods

to realize the space rescue and evacuation in case of

emergencies due to different reasons. The road

network structure in emergency regions would have

direct impact on the draft of evacuation plans, the

efficiency of evacuation in case of emergencies and

the disposal of emergencies. Starting from the

integrated development of Bohai rim megalopolis,

Tianjin’s emergency transportation system guided by

the world city by Tianjin and Beijing, will realize the

building and sharing of the infrastructures.

At present, Beijing-Tianjin corridor enjoys good

traffic conditions, which includes

Beijing-Tianjin-Tangshan expressway, Jingjin

expressway, Beijing-Tianjin intercity railway,

Beijing-Shanghai high-speed railway, Jingshan

railway and Beijing-Tianjin highway, but obviously

lack of channels in edge of north and south district. To

improve the overall capacity, we should enhance the

traffic corridor with the built of the second airport of

Beijing which connects to Tianjin Nangang, Jinghai

and Langfang by the south and has only one traffic

route—Tianjin-Shanxi highway that connects to 112

highways. And we should strengthen the contact

between Beijing airport and Baodi, Hangu and

strengthen the direct traffic links.

3.4 Establishing Public Safety Management System

Based on Regional Cooperation and Coordination

(1) The shift of public safety management from

single disaster management to full management

covers the draft of integrated strategy, policy, disasters

management plan, arrangements and support system

of resources;

(2) The risk management of public safety should

run through the whole process of the disasters. In case

of no disasters, we should conduct daily risk

management, namely prevention and preparation,

during the disasters, we conduct emergency risk

management, namely, emergency and rescue. After

the disasters, we conduct crisis risk management to

restore and rebuild the city;

(3) Public safety management places much

emphasis on management integration of different

parties (government, civil society, enterprises,

international world and international organizations) to

shape a mechanism of integrated leadership,

cooperation, and sharing interests and responsibilities.

It includes the integration of organizations,

information and resources;

(4) Public safety management should shift from

pure crisis management to risk management and

combine with daily public management of

government;

(5) For effective management of public safety,

government should establish integrated performance

indicators of public safety management. We should

keep an eye on the occurrence and change of disaster

risks, and provide full inspection to public safety

management departments in terms of their purposes

and methods, and the performance of staff and the

main departments.

4. Conclusions

Bohai Rim is one of the three major economic

zones of China with the other Pearl River Delta and

Yangtze River Delta. Bohai rim megalopolis is

identified as one of the three most important

megalopolis of china according to National

Development Priority Zones Planning and is aiming to

a world-class megalopolis. Tianjin is the important


1208

city in Bohai Rim area with the neighborhood of

China capital Beijing. So Tianjin urban public safety

planning includes not only comprehensive disaster

prevention and reduction, effectively preventing and

reducing disasters, ensuring the safety of the life and

property of the residents, which is the main content of

traditional public safety planning, but also sharing

resources and facilities from the view of megalopolis,

eliminating hidden area troubles, reducing whole

environment risks and so on. And Tianjin should

assume responsibility to perfect the contents and

method of urban public safety planning from the view

of region.

References

[1] Research on Comprehensive Disaster Prevention

Planning in Tianjin Urban and Rural District, Tianjin

Urban Planning and Design Institute, 2010.

[2] Research on Tianjin Urban Public Safety Planning,

Tianjin Urban Planning and Design Institute, 2012.

[3] Tianjin Urban Planning and Design Institute, Research on

Space Developing Mode of Bohai Rim Megalopolis,

Tianjin Planning Bureau, Tianjin Planning Academy, 2011.

[4] W.J. Shi, Research on space developing mode of

Bohai rim megalopolis, Bohai Economic View 10

(2011) 3-9.


Improving Conviviality in Public Places: The Case of

Naples, Italy

Gabriella Esposito de Vita1, Carmelina Bevilacqua2 and Claudia Trillo3

1. IRAT National Research Council of Italy (CNR), Naples 80134, Italy

2. Department of Heritage, Architecture, Urban Planning (PAU) University Mediterranea, Reggio Calabria 89124, Italy

3. School of the Built Environment (SOBE), University of Salford, Salford M54WT, UK

Abstract: Under the umbrella concept of conviviality in public spaces, a research project on the rehabilitation of urban areas for commercial and retail uses—as engine of a complex process of production of places for social and cultural mixité—has been defined. The aim of this research has been to produce useful tools for coping with the abandonment of public spaces in former commercial urban areas, without generating anonymous and globalized commercial districts. Through involving local stakeholders in a participatory process, the first phase of the research here presented needs to demonstrate the possible effectiveness of a pilot action plan in dealing with both isolation and gentrification processes of historical centres. The main hypothesis is that traditional retailers should be considered an essential element to ensure effective public use of urban public spaces. The research methodology is based on a qualitative approach. Focussing on the process of impoverishment within local commercial districts, the research group started working with local stakeholders in order to identify priorities and criticisms for enhancing a regeneration process. The case study to be carried out in Naples is the historical market place of Piazza Mercato in the Città Bassa of Naples (Italy). Key words: Public places, traditional retail areas, urban regeneration, historical centres, conviviality, Naples.

1. Introduction

The contemporary city is affected by a profound

crisis due to the loss of cultural identities, of

traditional social networks and of welcoming urban

spaces for improving interactions between diverse

components of society [1]. Places of public life are the

expression of this scenario: the agora is changing

forms, functions and symbols, following new trends

superimposed by globalization phenomena [2]. The

impact on the transformation of public places due to

recent dynamics, is revealed by the tendency to

produce market-led transformations of public places in

affluent areas and the abandonment and decay of the

peripheral public realm [3].

In the following pages, a research project will be

presented which is aimed at identifying the main

components of a process of rehabilitation of urban

Corresponding author: Gabriella Esposito de Vita, Ph.D.,

researcher, research fields: urban design, community planning and social activation. E-mail: [email protected].

areas for commercial and retail uses in order to favour

social and cultural mixité and economic regeneration.

The project deals with the increasing globalization

process, and consequently with the expulsion of

traditional and identitarian commercial activities from

the city centre, creating ruptures in the continuity of

the urban grid in terms of creation of market-led and

anonymous commercial areas on the one hand, and in

terms of abandonment and decay of less affluent areas

with a strong local cultural character on the other [4].

The research starting point is the role played by

traditional retailers and artisans as an essential

element to preserve local cultural character, ensuring

effective public use and liveability of urban public

spaces. The privatization and commercialization of

public and quasi-public places in affluent or

well-connected areas of the city, on one hand, and the

decay and abandonment of public places in deprived

areas, on the other hand, they are both causes and

effect of the social transformations. Economic crash,

DAVID PUBLISHING

D

Improving Conviviality in Public Places: The Case of Naples, Italy

1210

transformation of the job-market, dynamics and

quantities of migratory flows are strictly related to the

tendency of living in gated communities and

privatized public places dedicated to a forced

conviviality. The idea of convivium could be the

umbrella concept for surveying, interpreting, assessing,

designing, managing public spaces as places of

multicultural identity, security and security perception,

democracy and discussions, ethic and aesthetic and

human development [5]. This qualitative approach

aims at defining a holistic methodology for

interpreting, designing, managing and assessing the

refurbishment and redevelopment of those specific

areas. This topic will be addressed by developing an

urban design tool based on an effective participatory

process in the rehabilitation and redevelopment of

public places in abandoned commercial areas [6]. This

tool could be applied within community planning

consolidated methods [7-9], in order to better address

the physical and spatial component of the mapping

and visioning process. Consolidated procedures for

collecting and sharing the demand expressed by local

communities in terms of services delivery and public

places organization have been developed in different

fields of knowledge [10]. Nevertheless, there is a lack

of procedures for addressing demand for spatial

transformations in order to favour the preservation and

development of traditional and identitarian artisanal

and retail areas as a driver for a wide urban

regeneration process [11].

In order to identify the way physical and functional

transformations of commercial areas in city cores can

favour results in terms of social cohesion, economic

development, cultural preservation and local

liveability, the study started by working with a case

study approach [12].

The research focuses on the specific experience of

Naples in southern Italy, which offers a wide range of

interesting fields of reflection on the research topics.

The group of scholars and local technicians involved

in the fieldwork started doing active observations of

the Neapolitan urban area in order to identify possible

significant case studies to be carried out. The

conceptual map of significant areas was discussed

with local key actors such as: academics in the field,

technicians involved in the urban planning and

management, members of the local governing bodies,

activists from local NGOs (non-governmental

organizations) involved in topics such as job creation,

civic activation and urban regeneration as well as local

communities. The discussion resulting in the selection

of the historical market place of Piazza Mercato and

its neighbourhood in the Città Bassa district as a case

to be analysed because of the specific issues related to

artisanal and retail traditions combined with the

abandonment of public places and the impoverishment

of economic activities on the one hand, and because

this area has been the core of the Local Action Plan

implemented within the framework of the CTUR and

Hero Projects of the URBACT II Programme.

The fieldwork has been developed according to the

rationale of the EU-funded research “Commercial

Local Urban District Programme” led by the PAU of

the University Mediterranea of Reggio Calabria (IT)

“aimed at emphasizing the strategic role of small

retailers—handcraft and typical food—in reinforcing

the sense of community, reducing transportation costs

and contributing to the creation of an attractive urban

environment, thus producing an increase in private

investment” [13].

Through the experience gained during the execution

of the Local Action Plan for this historical area in

southern Italy, this paper aims at introducing and

discussing a work in process oriented to coping with

the tendency to abandon wide core areas of the city

centre by supporting virtuous processes of urban

regeneration, and intervening through a participatory

process in the rehabilitation of traditional and natural

market areas.

This paper is divided into four sections. Having

introduced the research in this section, the following

three sections aim to:


1211

• Set the context to identify the theoretical and

methodological context of urban design, community

planning and economic procedures to be applied

together to commercial urban districts regeneration;

• Define the framework for the empirical analysis

and discuss the pilot area findings;

• Draw general conclusions, defining the role of

local commercial areas as divers of urban regeneration.

2. Setting the Theoretical and Methodological Context

Every city is a human creation, but only a few

cities—in certain historical moments—have

developed a successful expression of public spaces as

trans-community agora suitable for liberating identity.

In those cases, cultural cross-pollinations have led to

the creation of particular architectural and urban forms,

which generate a physical-functional-relational milieu

[14].

“Public space, if organized properly, offers the

potential for social communion by allowing us to lift

our gaze from the daily grid, and as a result, increase

our disposition towards the other” [15]. Shared

spaces have played, on the one hand, the role of

symbols of collective well-being and formation of

civic culture and, on the other hand, of agonistic

struggle and social conflicts. “In an age of urban

sprawl, multiple usage of public space and

proliferation of the sites of political and cultural

expression, it seems odd to expect public spaces to

fulfil their traditional role as spaces of civic

inculcation and political participation” [15].

The history and culture of European cities reveal

the importance of public spaces such as streets and

squares, which are deeply influenced by the

commercial functions they host. Over the centuries,

local retailing models, often integrated with the

production of typical services, handcraft traditions and

locally produced food, have frequently conditioned

forms and organization of the European city (Fig. 1).

More generally, a higher level of manufacturing,

commercial and residential integration, is still related

to vibrant urban environments, which are rich in urban

life and social relations [16]. The contemporary public

space is the urban place that, more than others, has

been influenced by recent transformations of

production-related activities and of human behaviors,

spatial codes and use models of public spaces—for a

long time completely unchanged—have been affected

by the acceleration of the dynamics of the urban

system [17]. In accordance with Habermas’

observation that “public spaces become the object of

practices of cultural representation, with which the

public sphere is arguably more and more concerned”

[18], the research deals with the holistic idea of public

places as an expression of the cultural gaps within a

conflicting society and, at the same time, as place for

improving conflict-solving practices by favoring

public gathering. The first node to be tackled is the

lack of a shared vocabulary concerning the recent

expressions of public spaces, of private spaces with a

public use and of public spaces with a private use

[19-22]. Some provocative questions could be evoked,

as the editors did in Architecture and Dispersal: “What

constitutes public space in the contemporary city? Can

the public sphere still exist in the urban context?

Should public space be fought for by architects and

urban designers?” [23]. The everyday use of public

space has been changing from necessary uses to

optional, recreational uses. This changing role

increases the need for appropriate, well-designed

places in which people choose to spend time, and that

provide a place for people to relax, socialize and be

part of urban life” [24].

From the social point of view, it is widely

recognized that integrated urban environments often

contribute to a higher level of safety because of the

social control exercised on the public spaces due to

their continuous use, for the same reason, they are

less likely to became blighted areas, thanks to the

involvement of local communities in preserving their

values [25, 26].


1212

(a) (b)

(c) (d)

Fig. 1 The European city: (a) Commercial areas in the city centre of Eltville am Rhein (2008); (b) Castle Valentino Park in Turin (2011); (c) a square in Venice (2010); (d) the refurbished transport node of Montesanto in the historical centre of Naples (2009) (Photomontage by the authors).

From the environmental point of view, the

residential and commercial balance in each area is a

fundamental tool in securing a less car-oriented living

model, as small retailers allow residents to meet their

everyday needs by walking, thus, it represents a real

and proper pillar in ensuring a sustainable urban

lifestyle [27]. Furthermore, the link between small

retailers and niche local production helps to ensure a

more consistent and efficient supply chain, avoiding

useless freight transportation costs, as well as

reinforcing the relationship between the urban and

rural environments [28].

Although these are remarkable and valuable

features in the traditional European urban model,

nowadays the changes in the international retail

organization system are deeply impacting on the

commercial functions of some urban areas. In

particular, shopping malls and other large shopping

centres present potential forces for dramatically

reshaping the urban and suburban landscapes.

The research project, starting from the theoretical

perspective described, aims at defining a participatory

process to physical rehabilitation and

social-economics regeneration centred on the

enhancement of local art-and-crafts and retail

traditions. The participatory process needs to be

developed through involving local stakeholders such

as: local authorities, entrepreneurs, retailers and

artisans, representatives of local services, developers

and planners, academics involved in research and

education activities related to the area and

representatives of local communities.

The conceptual framework consists of the

possibility of merging urban design, community


1213

planning and economic procedures in order to build a

new tool for renovating degraded public spaces and

improving the attractiveness and accessibility of

deprived urban areas by focussing on the high

potential of local commercial activities. The research

can assist policy-makers in coping with the needs of

urban regeneration by setting up an analytical process

to understand how a public-private partnership

oriented to sustain local retail can be both market-led

and social-led.

In the 1990s, the PPPs (public-private partnerships)

have been considered as a key tool of public policy

across the world [29]. In some cases, PPP

(public-private partnership) can be considered as a

cooperation between public and private sectors for

developing services through risk and cost sharing. In

other definitions, PPPs are informed on a mutual

commitment between a public sector organization

with any other organization: from non-profit NGOs to

private companies market-led. As concern the balance

of roles among partners, in PPP’s both public and

private parties share costs, revenues and

responsibilities [30]. There are different forms of

mutual commitment, of cost and revenue sharing and

of subjects participant in PPPs oriented to

regeneration processes [31]. In Italy in the 1990s, the

planning culture has been massively interested with

the integrated programs experience [32], and the

definition of partnerships between local

administrations (such as city council) and developers

and other investors on the private side.

The research starts by highlighting integrated

approaches related to credit access, local resources

promotion, job creation, typical retail protection and

community engagement—in order to understand how

the territorial milieu can contribute to create the

necessary critical mass for improving local urban

regeneration initiatives [33].

In so doing, the development of the case study

approach has been conducted under the umbrella of

the Local Action Plan implemented within the

framework of the CTUR and Hero projects of the

URBACT II Programme in Naples.

3. Case Study Analysis: The Local Action Plan of Naples Città Bassa

The research here presented has been developed

along diverse routes for empirical applications. In

particular, two projects guided by local

administrations and oriented to make possible a wide

public-private partnership have been chosen to cross

the theoretical premises with a case study approach.

The projects “Cruise activity and the recovery of

urban and harbour building heritage: strong elements

of the common interest of sea towns to develop and

strengthen the urban tourism sector” (CTUR) and

“Heritage as Opportunity” (Hero) of the URBACT II

Programme [34] have been both developed

(2008-2011) by a network of European cities. The

core idea of the first one has been to improve

competitiveness and liveability of port cities through

the waterfront revitalisation (including derelict

industrial areas) in an overall approach of the port city

development, creating a mix between maritime and

urban activities within the framework of an integrated

approach of sustainable development. The second

project—dealing with the challenging management of

historic towns in Europe—focuses on heritage cities

throughout Europe, in order to enhance balance

between the safeguarding of heritage and the

development of the city, taking heritage as an

economic driver. These projects are both completed

and are now in the process of being implemented in

the local policies and are the base of the new projects

promoted by the Neapolitan City Council in order to

deepening the concept of land consumption in the

historic centre.

Briefly, Naples can be considered one of the

prominent ancient settlements in Europe and part of

the Mediterranean basin (Table 1). Its historic centre

is a unique example of architectural stratification

through the centuries and is still a vibrant catalyst of


1214

mixed activities without any museumification

phenomena. Along with these positive aspects there

are many problems, such as the high population

density, the low education indexes, the severe status

of the labour market linked to the lack of private

activities and job creation initiatives, the presence of

criminal organizations and the strong rehabilitation

needs of the built environment, including the cultural

heritage.

The complexity of this local scenario of resources

and challenges is the humus for nourishing the local

initiatives we have chosen as paramount cases to be

described [35].

The first step has been the definition of the case

study domain in terms of location, size, functional

organization and general characteristics. Through the

dialogue with the Urban Planning Department of the

City of Naples, the active observations in different

daytimes, weekdays and seasons as well as the

discussion with local stakeholders and scholars in

charge, a specific area involved in these

comprehensive projects has been chosen in order to

address the topics of the research.

The coexistence in the same area of various urban

planning and management tools, of several UE-funded

initiatives as well as of grassroots movements and of

traditional local economic activities can be considered

the ideal scenario for developing a complex

participatory process of urban regeneration to be

tested and generalized. The research in progress here

introduced has been developing in parallel and—on

some topics—in cooperation with the planners in

charge for the cited URBACT projects conducted by

the City of Naples (Table 2).

The area of Città Bassa, despite having previously

had a strong commercial character, suffers since the

end of the Second World War relative neglect and

gradual decay. In this context, some relevant key

issues can be pointed out with regards to: the physical

aspects such as location, accessibility, built

environment conditions, cultural issues such as

historical heritage, monuments, arts and crafts

traditions; and social scenario in terms of social

deprivation indices (Table 3).

The work is premised on enhancing local

revitalization and regeneration processes by focussing

on the potential of an integrated approach to

commercial activities, among the key issues related to

the urban revitalization of the historical urbanscape.

This is to be addressed in Naples by meeting the needs

of different stakeholders—the linkage with the cited

URBACT projects is “to secure traditional shops and

retail trade structures as these ones are struggling to

survive and to set up new governance structures for a

better coordination of the revitalization activities” [34].

The focus area for Hero projects is Piazza Mercato,

which is connected to an overall URBACT LAP named

“Città Bassa” [34] included in a comprehensive

intervention called “The waterfront of the historic

centre and port area from piazza Municipio to piazza

Mercato: a sustainable development through the

improvement of the cruise tourism impact”, which also

concerns the LAP of the URBACT Thematic Network

CTUR (Cruise Traffic and Urban Regeneration) lead

by the City of Naples [36].

The area of Città Bassa of Naples reflects all the

issues, criticisms and potentiality related to the

integration of typical handicrafts, dense residential

uses, traditional commercial activities and the

historical character of public places. This wide and

articulated area lies between the port and the historical

centre which has been listed as a World Heritage Site

by UNESCO since 1995 (Fig. 2).

The study area is included in the range of influence

of the Local Action Plan built by the city with the help

of its LSG (local support group), within the

framework of the URBACT projects. The LSG as

defined by Hero is to support the development and

implementation of the Integrated Cultural Heritage

Management Plan, which is “oriented towards the needs

of the historic urban area and its users, offers the

unique opportunity to bring the different stakeholders


1215

Table 1 Naples at a glance.

Classification Properties

Location Capital of the Region of Campania—Southern Italy

First settlement VI century B.C. as a Greek settlement

Population 1,004,500 inhabitants (City Council of Naples, census 2001)

Pop. density 8,556 inh/sq km (City Council of Naples, census 2001)

Unemployment rate 31.39% (City Council of Naples, census 2001)

Income per capita €25,565.81 (Finance Ministry, 2009)

Historic centre UNESCO recognizes the OUV (outstanding universal value) of the historic centre of Naples (1995)

Table 2 Plans and programmes which coexist in the study area. Plans and programmes Study area

They connected to the ERDF 2007-2013

DOS (Strategic Guidance Document) Integrated Urban Plan EUROPE for the historic centre of Naples (PIU EUROPA) Grande Programma UNESCO (UNESCO Great Programme) Strategic Plan of Naples Hero “Naples Historic Centre World Heritage Site Management Plan (WHSMP)” “Project of renewal of Borgo Orefici” under 2000-2006 ERDF Funds

Table 3 Città Bassa: some relevant aspects.

Classification Properties

Location Enclave between the port area and the historic centre UNESCO WHS

Accessibility

15 km from Capodichino International Airport Near the Central Railway Station Served by four metro stations (2 of those need to be completed) Near the local and regional maritime transportation nodes of Beverello Quay and Porta di Massa Quay

Historical heritage

Porta Nolana gate of the ancient city walls The renaissance church of SS. Cosma e Damiano The ruins of Castel del Carmine The baroque church of Santa Maria del Carmine Sant’Eligio Maggiore Church of the Angevin period dated 1270

Art and crafts tradition

Borgo degli Orefici (goldsmith quarter) since the fourteenth century Piazza Mercato Old Marketplace Antiche Botteghe tessili (textile market) Typical handmade street food

Social deprivation Unemployment rate (Mercato district 38.01%, Pendino district 40.37%) Illegal immigration Hidden and informal economic activities

Built environment

Low level of housing maintenance and technological retrofitting Abandoned and decayed public places Lack of spaces for pedestrian uses due to cul-de-sacs, squares transformed in parking areas, inefficient street lighting, abandoned ground floors (38% unused sqm—source Si.Re.Na Company) Buildings which provide physical and visual barriers between the area and the waterfront

together” [34]. The Neapolitan LSG has been formed

as the first step of the URBACT projects and has

become the main interlocutor of the different kinds of

local initiatives such as research fieldworks,

entrepreneurships, training and programmes for the

control against informal and hidden economy.

The fieldwork here presented has been oriented to:

• Collect, analyse and compare the initiatives

promoted within the EU-funded projects CTUR and

Hero with the other top down initiatives promoted by

the City Council of Naples;

• Develop a session of active observations,

informal interactions with people met in the area,

morphological analysis;

• Participate in focus groups, local initiatives,

meetings with local stakeholders;


1216

• Discuss with local stakeholders the results of the

LAP activities and the relevant questions emerged

through participation in the activities of the LSG.

The results of this fieldwork could be summarized

in the general idea that the LAP (Local Action Plan)

of Naples Città Bassa could become an experience of

paramount importance due to its mixed and complex

character (Table 4). Focussing not only on social

indices and economic issues, the added value of the

LAP can be considered the capacity of integrating

both the approaches: built environment and historic

heritage rehabilitation on the one hand and economic

strategies on the other. Within the LAP of Naples

Città bassa emerges a strategic approach in focusing

on the reconnection of the historical city centre with

the harbour as engine for enhancing the vitality of the

commercial district included in the area. The

economic stakeholders (retail consortia, artisan

consortia, shipping developers, building developers)

suggested to enhance the LAP through collecting

resources in order to support the specific rehabilitation

projects included in the plan. The priorities emerged

are: the development of sustainable tourism, the

creation of business incubators related to the

traditional artisanal and retail activities of the area, the

increasing of commercial attractiveness through

enhancing accessibility to the area, and job creation in

specialized fields. From both the economic and social

side, the stakeholders involved have identified as

result obtained by the LAP the impact achieved at the

local level by transferring the knowledge acquired in

the URBACT process to local policies, programmes

and actors. This has been accomplished by scaling-up

some of the action plans at the policy level and

integrating them into mainstream services, as well as

by securing funding through the Operational

Programmes of the ERDF (European Regional

Development Fund) for their implementation (Table 5).

Every subject interviewed agrees that the process has

also contributed to creating new partnerships between

Fig. 2 The study area of Città Bassa of Naples and Piazza Mercato (Courtesy Stefania Oppido).


1217

Table 4 Città Bassa LAP: main aims and objectives.

No. Main aims and objectives

1 Requalification of the waterfront monumental area and nearby historic urban area

2 Refunctionalization of the city and the port heritage

3 Maximize the economic and social impacts of the projects

4 Support the social and economic development of the “Città Bassa” quarter based on historical activities

Table 5 Città Bassa LAP: flagship projects investments (CTUR and Hero).

Projects Responsible Funds allocated Source

Cultural heritage safeguarding—building restoration

Old Monastery Carminiello (School) City of Naples 3,000,000 ERDF 2007/2013

S.Eligio Monastery 2,500,000

Borgo Orefici requalification SiReNa 17,670,000 Public/private

S.Maria Portosalvo Church Private 1,200,000 Private

Public places requalification City of Naples 5,140,000 ERDF 2007/2013

Requalification of complex ambit in the area 10,000,000 ERDF 2007/2013

Underground parking and requalification of related areas 13,500,000 ERDF 2007/2013

Business incubator for goldsmith and textile activities City of Naples Private consortia

1,000,000 ERDF 2007/2013 Private funds

Tramlines and requalification of via marina City of Naples 4,203,491

13,997,299 ERDF 2000/2006 Public/private funds

Shuttle connection to the maritime nodes Port Authority of Naples

750,000 Port Authority of Naples

Sources: Hero Flagships Projects 2011 and CTUR Naples Local Action Plan [37].

different levels of government and the involvement

and participation of private stakeholders in the

development of the project. The LAP has been

developed through the active participation of different

categories of local stakeholders, designing a new

possible structure of PPP.

4. Conclusions

The complex and articulated scenario of PPP tools

offers the possibility of identify a possible dynamic

system of relationships between subjects, actions,

resources, roles and evaluation of the results. In

particular, the case study approach is needed to design

a sort of fuzzy-architecture of the partnership models

aimed at facilitating local private and public initiatives

within the framework of the common interest of

generating social and economic enhancement. A

bottom up approach, oriented not only to collect

demands and needs from the territory but also to

encourage private initiatives, start-ups, non-profit

organizations, and other forms of investments, will be

elaborated and discussed with local stakeholders.

Starting from the virtuous process launched within

the framework of the URBACT LAP here analysed

and applying the methodological premises of the

CLUDs project, an adaptive model of urban

regeneration based on commercial activities is

currently being defined—in cooperation with the local

stakeholders involved in the transformations of the

study area.

Evidences from the fieldwork states that in specific

conditions local traditional commercial areas could

play an important role as drivers of urban regeneration

and cultural enhancement. The conditions identified

are:

• The former or current presence of local art &

craft and/or cultural traditions that could be the media

for enhancing the collective sense of belonging to the

area and building the critical mass for developing a

regeneration process;

• The activation of bottom up (predominantly

private) and/or top down (predominantly public)


1218

projects oriented to support local initiatives in terms

of social activation, job creation, place branding,

public places rehabilitation;

• The participation of local economic and social

stakeholder to the decision making process in order to

better address priorities and resources.

In the context analysed, the LAP has been

considered an important instrument for merging

together the above conditions and for encouraging the

dialogue between the stronger stakeholders of the

LAP area, such as the Port Authority, the City Council

and the other public actors involved on one side, and

the communities, the arts and crafts private consortia,

the developers and the port operators on the other side.

By setting up the local support group, the URBACT

projects acting in the area have created a positive

process: first, the initiatives developed by public

bodies started the auditioning process and the

collection of resources; subsequently, private bodies

and civil society have become part of the process.

As we can see, in the LAP experiences analysed,

the initiative starts with the involvement of public

bodies whose activites are primarily oriented to

identify priority for public investments and to engage

other public and private stakeholders. This process has

been developed by the City of Naples and the LSG

using a wide participatory process involving different

categories of city-users, producing a huge data and

information collection from the territory, providing a

big effort in terms of sourcing and integration of

financial resources and involving different categories

of city-users.

The institutional architecture of the partnerships

between public and private actors in the area and the

relationships between these partnerships and the

projects funded in the area depends on the National

Operational Programme of the Campania Region

funded within the ERDF 2007/2013. The LAP can be

considered the process for bringing together the local

initiatives with the main flagship projects funded by

the public sector, in order to enhance the results of this

bottom up approach by creating the humus for

nourishing the non-profit private initiatives of urban

regeneration driven by the development and

rehabilitation of commercial areas in a wide profitable

and marketable way.

The next step of this ongoing research should be,

according to the CLUDs rationale, the investigation of

the potentiality of the territorial milieu in enhancing

the building capacity of the commercial local districts

in the city core.

Acknowledgments

This presentation draws from the cooperation

between the research program CLUDs funded within

the framework of the EU IRSES Marie Curie 7FP and

the Urban Planning unit of the National Research

Council of Italy (CNR-IRAT).

References

[1] A. Madanipour, Whose Public Space? International Case Studies in Urban Design and Development, Routledge, London, 2010.

[2] M. Carmona, S. Tiesdell, T. Heath, T. Oc, Public Places Urban Spaces: The Dimensions of Urban Design, Routledge, New York and London, 2010.

[3] A. Madanipour, G. Cars, J. Allen, Social exclusion and space, in: R.T. LeGates, F. Stout (Eds.), The City Reader, Routledge, New York and London, 2011.

[4] M. Augé, Non-lieux, Editions Seuil, Paris, 1992. [5] H. Shaftoe, Convivial Urban Spaces: Creating Effective

Public Places, Earthscan, London, 2008. [6] P. Healey, Collaborative Planning: Shaping Places in

Fragmented Societies, Macmillan, London, 1997. [7] N. Waters, The Community Planning Handbook,

Earthscan, London, 2000. [8] H. Sanoff, Community Participation Methods in Design

and Planning, John Wiley and Sons, New York, 2000. [9] S.R. Arnstein, A ladder of citizen participation,

Journal of American Planning Association 35 (4) (1969) 216-224.

[10] S. Sassen, The Global City, Princeton University Press,

Princeton, 1991.

[11] T. Beatley, K. Manning, The Ecology of Place: Planning

for Environment, Economy and Community, Island Press,

Washington DC, 1997.

[12] R.K. Yin, Case Study Research, Design and Methods, 3rd ed., Sage Publications, London, 2003.


1219

[13] CLUDs Commercial Local Urban Districts, Research Concept, http://www.cluds-7fp.unirc.it/concept.php (accessed Apr. 10, 2011).

[14] F. Choay, P. Merlin, Dictionary of Urban Planning and Management, Gallimard, Paris, 2000. (in French)

[15] A. Amin, Collective culture and urban public space, City 12 (1) (2008) 5-24.

[16] D.W. Brinkerhoff, J.M. Brinkerhoff, Public private partnerships: Perspectives on purposes publicness and good governance, Public Administration and Development 31 (1) (2011) 2-14.

[17] M. Crang, Public space, urban space and electronic space: Would the real city please stand up?, Urban Studies 37 (2) (2000) 301-317.

[18] J. Habermas, The Structural Transformation of the Public Sphere: An Inquiry into a Category of Bourgeois Society, Hermann Luchterhand Verlag, Germany, 1989.

[19] S. Carr, M. Francis, L. Rivlin, A. Stone, Public Space, Cambridge University Press, Cambridge, 1993.

[20] P. Howell, Public space and the public sphere: Political theory and the historical geography of modernity, Society and Space 11 (1993) 303-322.

[21] Naples Hero Local Action Plan 2011, http://urbact.eu/fileadmin/Projects/HERO/projects_media/LAP_NAPLES_FINAL.pdf (accessed Apr. 5, 2012).

[22] K. Worpole, Here Comes the Sun: Architecture and Public Space in Twentieth Century Europe, Reaktion Books, London, 2000.

[23] R. Segal, E. Verbakel, Cities of Dispersal, Architectural Design, Wiley, New York, 2008.

[24] J. Gehl, A. Matan, Two perspectives on public spaces, Building Research & Information 37 (2009) 106-109.

[25] J. Gehl, Life between Buildings: Using Public Space, 5th ed., Arkitektens Forlag, Copenhagen, 2001.

[26] D. McNeill, Fine grain, global city: Jan Gehl, public space and commercial culture in central Sidney, Journal of Urban Design 16 (2) (2011) 161-178.

[27] Z.M. Akkar Ercan, Public spaces of post-industrial cities

and their changing roles, METU (Middle East Technical University) Journal of the Faculty of Architecture 24 (1) (2007) 115-137.

[28] M. de Martino, A. Marasco, A. Morvillo, Supply chain integration and port competitiveness: A network approach, in: P. Evangelista, A. McKinnon, E. Sweeney, E. Esposito (Eds.), Supply Chain Innovation for Competing in Highly Dynamic Markets: Challenges and Solutions, IGI Global, London, 2012.

[29] S.P. Osborne, Public-Private Partnerships: Theory and Practice an International Perspective, Routledge, New York and London, 2000.

[30] M. Bult-Spierung, Strategic Issues in Public Private Partnerships: An Alternative Perspective, Blackwell Publishing, London, 2006.

[31] CLUDs Report 2012, Economic Development Strategies, http://www.cluds-7fp.unirc.it/docs/deliverables/wp1_final.pdf (accessed May 23, 2013).

[32] M. Ricci, P. Avarello, From the Complex Programmes to the Integrated Policies for Development, INU (National Institute of Urban Planning), Roma, 2000. (in Italy)

[33] A. Ball, Synergy in urban regeneration partnerships: property agents’ perspectives, Urban Studies 40 (11) (2003) 2239-2253.

[34] Naples Hero Local Action Plan 2011, http://urbact.eu/fileadmin/Projects/HERO/projects_media/LAP_NAPLES_FINAL.pdf (accessed Apr. 5, 2012).

[35] J. Gaber, S.L. Gaber, Qualitative Analysis for Planning and Policy: Beyond the Numbers, American Planning Association, Chicago, 2007.

[36] Naples CTUR Local Action Plan 2011, http://urbact.eu/fileadmin/Projects/CTUR/outputs_media/CTUR_Report-Finale-IT_def.pdf (accessed Mar. 6, 2012).

[37] Naples CTUR Local Action Plan 2011, http://urbact.eu/fileadmin/Projects/CTUR/outputs_media/light_def_LAP__CTUR_Naples_Port_Authority_En.pdf (accessed Jan. 15, 2012).


Design Drivers for Affordable and Sustainable Housing

in Developing Countries

John Bruen1, Karim Hadjri2 and Jason von Meding3

1. School of Planning, Architecture and Civil Engineering, Queen’s University Belfast, Belfast BT9 5AG, UK

2. School of Built and Natural Environment, University of Central Lancashire, Preston PR1 2HE, UK

3. School of Architecture & Built Environment, University of Newcastle, Newcastle 2308, Australia

Abstract: Current demand for housing worldwide has reached unprecedented levels due to factors such as human population growth, natural disasters and conflict. This is felt no more so than in developing countries which have experienced disproportionate levels of demand due to their innate vulnerability. Many current approaches to housing delivery in developing countries continue to utilize inappropriate construction methods and implementation procedures that are often problematic and unsustainable. As such affordability and sustainability are now vital considerations in the international development debate for housing the poor in developing countries in order to meet the long term sustainable development goals and needs of housing inhabitants. This paper utilized an extensive scoping study to examine the various facets impacting on design decision making relative to sustainable and affordable housing delivery in developing country contexts. Aspects of affordability, sustainability, design decision making, appropriate technology use, cultural awareness, as well as current barriers to affordable and sustainable construction in developing countries are examined in detail. Results highlighted the capability of indigenous knowledge, skills and materials as well as selected appropriate technology transfer and cultural awareness by foreign bodies can be utilized in innovative ways in addressing current housing needs in many developing country contexts. Key words: Sustainable housing, low-cost housing, design decision making, affordability.

1. Introduction

Shelter is one of the most basic human

requirements for survival. The provision of adequate

and appropriate housing can be deemed to address this

basic need. However, the provision of adequate

housing also meets more than human’s immediate

needs and has the potential to contribute significantly

to a wider social, environmental and economic context

and to a better quality of life and personal fulfillment

for its inhabitants through aspects such as

employment generation, knowledge transfer and

training, value and cultural continuity and improved

health conditions [1]. However, the struggle for

adequate housing in many developing countries is

considerable and set to continue to rise in future

Corresponding author: John Bruen, B.Sc., B.Arch., M.Sc., RIBA chartered architect, research fields: post disaster management and sustainable housing. E-mail: [email protected].

decades unless addressed.

As such housing is central to much international

debate in many developing countries. Vast numbers of

people find themselves without adequate shelter due

to housing shortages experienced in many of these

areas and this is well documented in current literature

[2-4]. However, much of the current literature

highlights various aspects that impact on the provision

of housing in various developing country contexts

worldwide without focusing solely on dwelling design

and the aspects that impact the designers decision

making, i.e., the barriers and drivers of design. This

paper provides findings from various developing

country contexts to enable the identification of

common aspects that impact designer’s decision

making in various developing country contexts

worldwide. Tipple [5] states that it is almost

impossible to determine the exact shortage of housing

DAVID PUBLISHING

D

Design Drivers for Affordable and Sustainable Housing in Developing Countries

1221

in the developing world due to limitations such as

insufficient data, little agreement on units of

measurement, the length of time data takes to collate

and publish and data going out of date very quickly.

Housing shortages can often be traced back to two

main sources as follows.

1.1 Pace of Growth of Developing Countries,

Governmental Policy and Countries History

The pace of growth and industrialization in many

developing countries has led to rapid urbanization and

increases in population. The UNCHS (United Nations

Centre for Human Settlements) estimates 95% of the

world’s total population growth in the last decade has

occurred in developing countries and that these

countries will contribute 2 billion new residents

during the next 25 years [3]. Between 2007 and 2025,

the annual urban population increase in developing

regions is expected to be 53 million compared to 3

million in developed regions [3]. This increase has

already resulted in severe housing shortages, urban

poverty and homelessness in many countries and the

development of slums/shanty towns/informal

settlements on the periphery of many major cities. As

a result, slum dwellers now represent more than 50%

of the population in many developing countries with

close to 1 billion people, or 32% of the world’s

current urban population, live in slums in inequitable

and life-threatening conditions [3]. As such, the

informal sector is recognized as the biggest producer

of housing in many developing countries [4].

1.2 Natural Disasters and Conflicts

The devastation resulting from natural disasters and

conflicts is most frequently observed in developing

countries due to innate vulnerability and lack of

knowledge and resources to adequately implement

disaster mitigation strategies or post disaster/conflict

recovery strategies. Between 1974 and 2003, 6,367

natural disasters occurred globally, causing the death

of 2 million people and affecting 5.1 billion people. A

total of 182 million people were made homeless. Of

these natural disasters a total of 98% of the 211

million people affected annually from 1991 to 2000

were in developing countries [2]. The devastation

caused by many of these scenarios involves the

destruction of much of an area’s built environment,

i.e., housing (shelter), hospitals, shops, schools etc.,

services infrastructure (water supply, heat and sanitary

requirements) transport infrastructure (roads, rail).

The destruction of these basic human requirements

has many consequential types of fallout such as

health, economic and social upheaval in the affected

country.

2. Methodology

As the research area is quite broad a scoping study

was selected as the most appropriate research method

for this review in order to summarize the key findings

from all available literature and also to identify the

potential gaps. This approach is particularly relevant

to this particular study as there are numerous sources

of information available from various organizations

and bodies, i.e., academic journals, industry journals,

international housing organizations, NGOs

(non-governmental organizations) etc.. In-depth and

broad findings on the topic were sought from current

available literature to enable conclusions and findings

to be disseminated to relevant stakeholders who may

lack the time or resources to undertake the study

themselves i.e. designers, policy makers, community

organizations, NGO’s. Arksey and O’Malley [6] state

that scoping studies are appropriate in this context as

they are guided by a requirement to identify all

relevant literature regardless of study design as

opposed to been guided by a specific research

question as may be the case in a systematic literature

review.

A five point framework developed by Arksey and

O’Malley [6] was utilized for this scoping study. This

framework firstly consisted of developing a research

question, secondly identifying the relevant literature,


1222

thirdly selecting the relevant literature, fourthly

charting the data and finally summarizing and

reporting the findings in a concise manner. The

selected research question was broad in nature to

cover the main aspects to be covered by the study:

“What are the main barriers and design drivers for

affordable and sustainable housing in developing

countries?”

In keeping with Arksey and O’Malley [6] proposed

framework and in order to generate a broad range of

coverage an extensive approach using selected

keywords was utilized to identify relevant data. This

consisted of journal publications searches in major

registers such as Avery, INFORM Global, Zetoc, Web

of Science and Compendex. A further internet search

using Google Scholar was utilized to further expose

publications or grey literature. Bibliographies and

references were studied to locate further useful

information for the study. Website searches of suitable

reputable organizations such as Un-Habitat, national

and international housing NGOs, housing charities

and open access journals, were examined for relevant

information, i.e., field reports, policies, case studies

etc.. The latter approach is quite a relevant data

collection method in relation to this particular topic as

open access to information and knowledge transfer,

with the aim of improving housing for the poor in

developing countries, is an aspiration of many

organizations operating in the field of housing

provision in developing country contexts and the

making available of their information is to be

commended.

Following elimination of irrelevant studies a total

of 649 references were identified from the various

searches outlined. Following further in-depth reading

of titles and abstracts 154 were selected for further

reading of which 55 were used in the final reference

list. Mapping of the findings were divided into various

headings and sub heading to address the overall

research question. The overall main headings

consisted of: (1) barriers and challenges to sustainable

construction in developing countries; (2) main design

drivers with the potential to contribute to

affordable and sustainable housing in developing

countries.

3. Current Approaches to Housing Design and Delivery

The two main causes of housing shortages outlined

share many commonalties in that in both situations

should the housing shortage be addressed using

conventional unsustainable construction techniques

then the environmental effect alone of this approach

would be devastating considering the vast scale of

housing required in developing countries. While the

majority of efforts by decision makers such as

governments, NGOs, CBOs (charity based

organizations), etc. to address housing shortages have

the best intentions of people central to their efforts,

the literature highlights that the current approaches to

housing shortages often involve a top down approach.

This means that many communities are not involved

in participation to the level that they should be to

ensure their short and long term settlement needs are

satisfied in an appropriate manner.

The global shortage of housing requires appropriate,

affordable and sustainable responses that cater to

severely affected regions worldwide. Erguden [1]

highlights that policies and approaches for housing in

developing countries have evolved over the past

number of decades from one centered on government

provided social housing to one of self-help to the

current common approach of enablement in which all

parties support a people centered housing process to

obtain housing delivery goals. Although the

enablement based approach is generally considered to

be the most appropriate many approaches currently

fall well short of the desired aspirations in relation to

affordability and sustainability. Reffat [7] states that

the concept of sustainability has only recently been

introduced into developing countries construction

industries and that sustainability and sustainable


1223

construction are not yet an essential part of the

decision making process. Traditionally, affordability

in mainstream housing markets is associated with

economic and social sustainability with little emphasis

on environmental sustainability [8]. Perceived higher

costs and underlying socio-cultural factors also

contribute to the lower levels of social acceptability of

sustainable construction in the main stream affordable

housing market [9, 10]. Global inequalities and

economic constraints in many developing countries

have also resulted in pragmatic governance decision

making in relation to sustainable social and

environmental goals being made more difficult [11].

In many instances, organizations have to provide

housing to meet the immediate term shelter needs of

large populations, at times due to natural disasters or

conflicts, and this is often given priority over long

term aspects such as sustainable design, participation

and reference to local materials and techniques.

Sustainability is thus often perceived as an additional

cost to standard practice and is not a necessity but

rather a luxury of the rich [7, 12].

Many current approaches to housing provision are

left to what professionals from the formal sector and

international bodies consider the most appropriate

solution which is often at odds with the expectations

of the future house inhabitants and environmental

ideals [13, 14]. Many current approaches often

employ a one hat fits all or quest for a universal

approach to addressing the current housing shortage in

developing countries. Often these approaches involve

imported industrialized materials, western

construction techniques and typologies not common to

the surrounding context. This is often due to the

perception that the “west knows best” and these

solutions are deemed to be associated with wealth,

progress, prosperity and globalization. This is a

flawed belief and demonstrates a clear lack of

understanding and vision on behalf of the different

decision makers involved in implementing these

approaches. This often results in rigid monotonous

constructions and typologies which ironically can

have negative effects on the end users long term needs

and wellbeing, i.e., replacement of traditional

settlements with modern towns and lack of cohesion

between the town’s inhabitant leading to

socio-cultural and economic negative effects [15]. The

manufacture and import of many of the materials used

also result in houses that are not affordable for the

masses of population that require them [16] as well as

being environmentally unsustainable.

4. Barriers and Challenges to Sustainable Construction

Various literature [4, 17-25] highlights the common

barriers faced in trying to implement sustainable

construction in developing countries:

• Environmental sustainability is often a low

priority in developing countries, and the need for

immediate shelter is primary for the majority;

• Psychological and sociological issues in relation

to use of alternative materials and its acceptability by

people, i.e., status of certain materials deemed for the

poor only;

• Effects of globalization and desire of many to

imitate housing approaches of the west leading to

inappropriate imported typologies, materials, designs

etc.;

• Lack of overall holistic approach to sustainable

design, i.e., social, cultural, economic and

environmental;

• Lack of training and education in sustainable

design and construction leading to lack of necessary

design and building skills available;

• Lack of access to adequate information and

knowledge on sustainable development and design;

• Inadequate government planning and policy

making;

• Perceived higher cost of sustainable building

approaches;

• Scarcity of professional capabilities, i.e.,

designers and project managers;


1224

• Lack of demonstration examples of best practice

sustainable construction approaches;

• Disincentive factors over local material

production, i.e., government supplying alternative

imported materials;

• Need to develop cost effective construction

technologies;

• Building materials are becoming ever more

expensive. Need to utilize locally available materials

to suit local typologies;

• Lack of guidelines available on selection of

appropriate building approaches and packages, i.e.,

materials, methods, designs, equipment;

• Unaffordable land and housing prices and lack of

land tenure;

• Inadequate housing finance systems;

• Lack of support of small scale construction

industries;

• Inefficient or inadequate implementation

strategies;

• Lack of research and experimental findings;

• Lack of implementation and promotion of

research findings on appropriate approaches;

• Gradual vanishing of traditional wisdom and

knowledge on local material and construction

techniques;

• Historical legacies of race and class;

• Lack of government or political backing to

sustainable development;

• Inappropriate procurement systems;

• Inability to adopt best practice;

• Bureaucratic impediments to the implementation

of housing;

• Inappropriate building regulations;

• Lack of consultation and capacity building with

housing inhabitants;

• Poor housing management and planning policies

at both a national and local scale in many countries.

In order to address these barriers and challenges a

clear and concise design approach is required to

identify them from the outset of projects and propose

methods of enabling designers and other stakeholders

to address them so as not to have a detrimental effect

on the long term overall affordability and

sustainability goals of the project.

5. Main Design Drivers with the Potential to Contribute to Affordable and Sustainable Housing in Developing Countries

This study focused primarily on the design

considerations of appropriate and suitable low-cost

sustainable housing to meet current shortages. The

literature indicates that in relation to the design of

dwellings there are three main broad areas that offer

the potential to significantly contribute to the

provision of affordable and sustainable housing in

developing countries.

5.1 Appropriate Design and Material Selection

Efforts to address immediate housing needs should

simultaneously address the long term needs and

sustainability of the communities which they intend to

serve in terms of social, economic and environmental

sustainability [17]. The increasing demand for

housing has resulted in an urgent need for crucial

research into new design approaches and use of

alternative materials in housing delivery [17]. Mehta

and Beidwell [26] argue that increasing the quality of

life in developing countries requires optimum use of

local natural resources and labor over imported

materials, increasing the potential for greater

affordability.

Material supply has been recognized by many as

one of the main contributors to the provision of

affordable and sustainable housing, contributing up to

70% of the total direct costs of housing construction

[25, 27-30]. The use of localized materials, skills and

construction techniques in design has the potential to

dramatically reduce the cost of housing compared to

westernized techniques, while simultaneously

contributing to sustainable housing solutions

[31-35].


1225

5.2 Participation, Knowledge Transfer and Use of

Appropriate Innovative Technology Specific to

Developing World Contexts

Despite the fact that over two thirds of the world’s

population live in developing countries, to date the

developed world has led the way in global

environmental destruction [36]. It is also developed

countries that have dominated research in relation to

sustainable construction, much of which is aimed

specifically towards a developed country context. This

has led at times to a non holistic approach to

sustainable housing with technical cost reduction

measures often employed to a large degree with little

consideration given to what housing means for its

users [37]. Many current approaches result in

conflicting and competitive issues in technological

economic sustainability verses cultural and social

sustainability [18]. There is recognition that

sustainable development approaches and technologies

established in the west are not always desirable and

the evidence shows that if not implemented correctly,

these approaches will prove unsuccessful [24, 37, 38].

New approaches need to be adopted for the vastly

different contexts within developing countries and

local conditions, knowledge and culture must be given

full recognition [39].

Participation by relevant stakeholders in all stages

of the design and delivery process has been

recognized as an appropriate approach to housing

provision in developing country contexts [40-43]

Knowledge creation, exchanging and sharing of skills,

knowledge and experiences between the relevant

stakeholders are recognized as effective approaches in

ensuring technical, cultural, economic and

environmental aspects of housing design and delivery

are addressed in an appropriate manner [1]. The use of

appropriate technology should work in conjunction

with design and materials and should correspond to

local conditions and culture and be durable, reliable,

require a minimum of maintenance and be fit for

modern living [27, 44].

Plessis [4] argues that although the level of

development required in developing countries may be

a cause of despair it can also be seen as an opportunity

to learn from developed nations, avoid the problems

experienced by developed countries, and follow a

more sustainable development path, of which housing

will play a major part. In addition, Plessis [45] argues

there is no clear guidance as to what sustainable

development of the built environment means and how

sustainable development can be incorporated into the

decision making process, further adding that the

academic debate in developed countries has little to

offer except where applies to the hi-tech world of the

West. She further states that in order for sustainable

development to be effectively addressed societies can

not isolate themselves and two way communication

and dialogue between developing and developed

countries is required. This sentiment is backed by

Cole and Lorch [46] who argue that environmental

issues require international cooperation in setting

agendas, targets, assessments and standards as well as

the sharing of sound environmental knowledge and

practice.

Much of what we know as transfer of knowledge is

attributed to factors such as globalization and

advanced technology and communications. However,

Oliver [47] highlights that cross cultural transfer and

exchange of knowledge and ideas has always existed,

it is just that it has never existed at such an accelerated

rate due to modern technology and globalization.

Vellinga [48] notes that globalization and the transfer

of technology between different cultures need not

necessarily be a cultural treat and that cultural

hybridity is nothing new, stating that the important

factor that influences its acceptance and success is the

opportunity to appropriate it to local traditions, ways

of life, cultural values and customs. As such Vellinga

[48] states that globalization can best be regarded as

an infrastructure which facilitates the appropriate

exchange and transfer of new ideas and practices

including green technologies for the built


1226

environment.

5.3 Design Decision Making Assistance and

Assessment Tools

Fray and Yaneske [49] suggest that the problem with

many responses to sustainability is that decisions are

made with limited knowledge and information.

Building and construction play an important role in

supporting sustainable development in developing

countries and as a consequence the vast demand for

housing is a significant issue that must be prioritized.

However, it is recognized that the relationship between

the two is a complex one and that an assessment

framework and structured approach are effective

methods to integrate sustainability into buildings in

developing countries [7, 50]. Sustainable assessment

tools to date have mainly focused on a developed world

context [51] and focus mainly on technological

solutions. Aside from established assessment tools from

developed nations, i.e., BREEAM (UK), LEED (US),

GBTool (Multi National), EcoHomes (UK) there is

little in the current literature to demonstrate the

existence of any main assessment tool specifically

directed to sustainable housing in developing countries.

However, the need to develop context specific

assessment tools for developing countries that cater for

a wider group of stakeholders has been recognized,

given that existing developed country tools are not

deemed appropriate [51-57].

6. Conclusions

This paper presented the findings of a scoping study

examining the various aspects impacting on the design

and delivery of affordable and sustainable housing in

developing country contexts worldwide. The paper

utilized various relevant information sources to

identify the main design barriers and challenges

designers operating in housing provision in

developing country context face and should be aware

of from the outset of their design projects. The study

further recognizes three drivers for design that if

utilized could offer the potential to significantly

contribute to the provision of appropriate housing

design and delivery in developing country contexts.

The study focused on aspects of sustainability

beyond environmental aspects alone and addressed

aspects such as economic and social elements which

all form the triple bottom line many experts associate

with sustainable design. It is concluded that the

aspects identified in this study can be addressed

through an informed design decision making process

which considers the various design challenges,

barriers and drivers as identified in this study. This

paper will assist in the decision making of the various

bodies and professions responsible for implementing

housing design and provision in developing country

contexts, i.e., governmental bodies, policy makers,

NGOs, CBOs, planners, architects, engineers and

developers.

This paper utilized information sources based on

many different developing country context worldwide

to identify design barriers, challenges and drivers that

are common to developing country contexts at large in

order to enable design practitioners in developing

countries to ensure these aspects are given due

consideration in their design decision making process.

The author recognizes that many individual

developing country contexts, or regions within

developing countries, will have individual or region

specific factors that will require more in-depth study

by designers operating within that context in order to

fully establish local design considerations in sufficient

specific detail to ensure appropriate design responses

for that specific region. As such further research

studies on individual developing country contexts by

both academics and practitioners of individual

countries or regions will enable more region specific

detail to be obtained under the various design

consideration aspects identified within this paper and

add to the knowledge base for designers operating in

that specific region or country. Appropriate

dissemination of design knowledge gained from


1227

individual contexts research is essential to ensure that

the various potential users identified above have

access to the relevant knowledge and guidance and

that it is utilized to its full potential in practice.

References

[1] S. Erguden, Low-cost housing: Policies and constraints in developing countries, in: International Conference of Spatial Information for Sustainable Development, Nairobi, Kenya, Oct. 2-5, 2001.

[2] Enhancing Urban Safety and Security—Global Report on Human Settlements 2007, UN-HABITAT (United Nations Human Settlements Programme), Earthscan, London, 2007.

[3] Planning Sustainable Cities: Global Report on Human Settlements 2009, UN-HABITAT (United Nations Human Settlements Programme), Earthscan, London, 2009.

[4] C. du Plessis, Agenda 21 for Sustainable Construction in Developing Countries: A Discussion Document, CSIR Building and Construction Technology, Pretoria, 2002.

[5] G. Tipple, Extending Themselves: User-Initiated Transformations of Government Built Housing in Developing Countries, Liverpool University Press, Liverpool, 2000.

[6] H. Arksey, L. O’Malley, Scoping studies: Towards a methodological framework, Int. J. Social Research Methodology 8 (1) (2005) 19-32.

[7] R. Reffat, Sustainable construction in developing countries, in: Proceedings of First Architectural International Conference, Cairo University, Egypt, 2004.

[8] B. Randolph, M. Kam, P. Graham, Who can afford sustainable housing, in: A. Nelson (Ed.), Steering Sustainability in an Urbanizing World, Ashgate, Aldershot, United Kingdom, 2008.

[9] L. Buys, K. Barnett, E. Miller, C. Bailey, Smart housing and social responsibility: Learning from the residents of Queensland’s research house, Australian Journal of Emerging Technologies and Society 3 (1) (2005) 43-47.

[10] J. Sibley, D. Hes, F. Martin, A triple helix approach: An inter-disciplinary approach to research into sustainability in outer suburban housing estates, in: Proceedings of Methodologies in Housing Research Conference, Stockholm, Sep. 2008.

[11] C. Sneddon, R. Howarth, R. Norgaard, Sustainable development in post Brundtland world, Ecological Economics 57 (2006) 53-268.

[12] P. Brandon, P. Lombardi, Evaluating Sustainable Development, Blackwell Science, UK, 2005.

[13] G. Lizarralde, C. Davidson, Learning from the Poor, IF Research Group, Faculté de l’Aménagement, Université deMontréal, Canada, http://www.grif.umontreal.ca/pages/

lizarralde_gonzalo.pdf (accessed Mar. 15, 2011). [14] A. Fallahi, Lessons learned from the housing

reconstruction following the Bam Earthquake in Iran, The Australian Journal of Emergency Management 22 (1) (2007) 26-35.

[15] Y. Kakabadse, The Essence of Sustainable Construction in on the Road to Sustainability—A Collection of Short Contributions from International Proponents of Sustainable Construction—Holcim awards June 2005, http://www.holcimfoundation.org/T702/HolcimAwards.hm (accessed Mar. 15, 2011).

[16] A.Y. Adeyemi, Affordable housing production: The influence of traditional construction materials, in: 30th IAHS World Congress on Housing, Housing Construction: An Interdisciplinary Task, Wide Dreams—Projectos Multimédia, 2002, pp. 827-832.

[17] Un-Habitat, Low-Cost Sustainable Housing, Materials + Building Technology in Developing Countries—Shelter Initiative for Climate Change Mitigation, www.gltn.net/....low-cost-sustainable-housing-materials-building-technology-in-developing-countries...-/download.html (accessed Mar. 3, 2011).

[18] N. Islam, Sustainability issues in urban housing in a low-income country: Bangladesh, Habitat International 20 (3) (1996) 377-388.

[19] A. Ngowi, Challenges facing construction industries in developing countries, Building Research & Information 30 (3) (2002) 149-151.

[20] A. Goebel, Sustainable urban development? Low-cost housing challenges in South Africa, Habitat International 31 (2007) 291-302.

[21] G. Ofori, Challenges facing the construction industry in developing countries, in: Proceeding of 2nd International Conference on Construction in Developing Countries, Gaborone, Nov. 15-17, 2000.

[22] F. Shafii, Achieving sustainable construction in the developing countries of South East Asia, in: Proceedings of the 6th Asia-Pacific Structural Engineering and Construction Conference (APSEC 2006), Kuala Lumpur, Malaysia, Sep. 5-6, 2006.

[23] R.K. Celly, Low cost energy efficient and environmental-friendly housing technologies for developing countries, in: Sanjaya Lall Memorial Conference on India-Africa Cooperation, Trade and Investment, New Delhi, Sep. 10-14, 2007.

[24] The Provisional Agenda Appropriate, Intermediate, Cost-Effective Building Materials, Technologies and Transfer Mechanisms for Housing Delivery, United Nations Centre for Human Settlements (UNCHS), 1992, http://www.unhabitat.org/downloads/docs/3636_21919_HS-C-16-2-Add_2.htm (accessed Mar. 15, 2011).

[25] J. Wells, Population, settlements and the environment: The Provision of organic material for shelter, Habitat


1228

International 19 (1) (2005) 73-90. [26] R. Mehta, L. Beidwell, Innovative construction

technology for affordable mass housing in Tanzania, East Africa, Construction Management and Economics 23 (2005) 69-79.

[27] J. Wells, S.H. Sinda, F. Haddar, Housing and building materials in low-income settlements in Dar es Salaam, Habitat International 22 (4) (1998) 397-409.

[28] M.S. Zami, A. Lee, Using Earth as a Building Material for Sustainable Low Cost Housing in Zimbabwe, The Built & Human Environment Review, 2008.

[29] P. Tiwari, Sustainable practices to meet shelter needs in India, Journal of Urban Planning and Development 29 (2) (2003) 65-83.

[30] D.R. Moore, N. Ahmed, Proposal for the development of an indigenous materials and methods—Oriented design data aid for design professionals practicing in developing nations, Habitat International 21 (1) (1997) 29-49.

[31] M.S. Zami, A. Lee, Economic benefits of contemporary earth construction in low-cost urban housing—State-of-the-art review, Journal of Building Appraisal 5 (2010) 259-271.

[32] K. Hadjri, M. Osmani, B. Baiche, C. Chifunda, Attitude towards earth building for Zambian housing provision, in: Proceedings of the ICE Institution of Civil Engineers, Engineering Sustainability 160 (2007) 141-149.

[33] A.O. Olotuah, Recourse to earth for low-cost housing in Nigeria, Building and Environment 37 (2002) 123-129.

[34] D. O’Brien, I. Ahmed, D. Hes, Housing reconstruction in Aceh: Relationships between house type and environmental sustainability, in: Conference Proceedings, Building Abroad—Procurement of Construction and Reconstruction Projects in the International Context, Montreal, Oct. 2008, pp. 361-370.

[35] K.J. Charles, U. Paul, Low cost construction technologies and materials—Case study Mozambique, in: Proceedings of the 11th International Conference on Non-conventional Materials and Technologies (NOCMAT 2009), Bath, UK, Sep. 6-9, 2009.

[36] B. Hamm, P.K. Muttagi, Sustainable Development and the Future of Cities, Intermediate Technology Publications, London, 1998.

[37] R. Lorch, Sustainable development and regionalism, Building Research & Information 33 (5) (2005) 393-396.

[38] E. Cromley, Cultural embeddedness in vernacular architecture, Building Research & Information 36 (3) (2008) 301-304.

[39] S. Guy, Cultures of architecture and sustainability, Building Research & Information 33 (5) (2005) 468-471.

[40] V.O. Cigdem, E. Yalciner, G. Nilufer, Local participatory mechanisms and collective actions for sustainable urban development in Turkey, Habitat International 35 (2011)

9-16. [41] M. Holden, M. Roseland, K. Ferguson, A. Perl, Seeking

urban sustainability on the world stage, Habitat International 32 (2008) 305-317.

[42] A. Maskrey, Disaster Mitigation: A Community Based Approach, Oxfam, Oxford, 1989.

[43] M.B.G. Choguill, A ladder of community participation for underdeveloped countries, Habitat International 20 (3) (1996) 431-444.

[44] C. Ebsen, B. Rambol, International review of sustainable low-cost housing projects, in: Proceedings of Strategies for a Sustainable Built Environment, Pretoria, Aug. 23-25, 2000.

[45] C. du Plessis, Sustainable development demands dialogue between developed and developing countries, Building Research & Information 27 (6) (1999) 378-379.

[46] R.J. Cole, R. Lorch, Buildings, Culture and Environment, Informing Local & Global Practice, Blackwell Publishing, Oxford, 2003.

[47] P. Oliver, Technology Transfer—A Vernacular View, in Buildings, Culture and Environment, Informing Local & Global Practice, Blackwell Publishing, Oxford, 2003.

[48] M. Vellinga, Sustainable architecture in an age of gentle apocalypse, Building Research & Information 32 (4) (2004) 339-343.

[49] H. Frey, P. Yaneske, Visions of Sustainability: Cities and Regions, Taylor & Francis, New York, USA, 2007.

[50] J. Gibberd, Building Systems to Support Sustainable Development in Developing Countries, Facilities Planning and Management, CSIR Building and Construction Technology, Pretoria, 2003.

[51] J. Gibberd, Assessing sustainable buildings in developing countries—The sustainable building assessment tool (SBAT) and the sustainable building lifecycle (SBL), in: 2005 World Sustainable Building Conference, Tokyo, Sep. 27-29, 2005.

[52] H.H. Ali, S.F. Nsairat, Developing a green building assessment tool for developing countries—Case of Jordan, Building and Environment 44 (5) (2009) 1053-1064.

[53] Y. Liu, D. Pradad, D. Li, J. Liu, Developing regionally specific environmental building tools for China, Building Research & Information 34 (4) (2006) 372-386.

[54] J.A. Todd, S. Geissler, Regional and cultural issues in environmental performance assessment for buildings, Building Research & Information 27 (4-5) (1999) 247-256.

[55] E. Kaatz, D. Root, P. Bowen, Broadening project participation through a modified building sustainability assessment, Building Research & Information 33 (5) (2005) 441-454.

[56] J. Turner, Tools for building community: An examination of 13 hypthosis, Habitat International 20 (3) (1996) 339-347.


Investigation of Bed Joint Reinforcement Influence on

Mechanical Properties of Masonry under Compression

Lukasz Drobiec

Department of Building Structures, Faculty of Civil Engineering, Silesia University of Technology, Gliwice 44-100, Poland

Abstract: The results of investigations of compressed reinforced masonry walls subjected to axial compression are presented. Tests were carried out using specimens made of clay bricks and cement-lime mortar. As reinforcement, smooth and spiral twisted longitudinal rods, two types of structural wire mesh and truss type reinforcement were used. Two percentages of bed joint reinforcement, about 0.1% and 0.05% were applied. For each type of reinforcement, three masonry walls were tested. Additionally, nine unreinforced models were also tested. The main aim of the investigations presented is to determine the effect of different types of reinforcement on the load capacity and failure. Measurement of the strains of reinforcing bars permitted the recording of the strain level at the moment of crack appearance and also at the moment of failure. Key words: Reinforced masonry, bed joint reinforcement, compressed masonry.

1. Introduction

Reinforcement has been used in masonry structures

for about the last 200 years. Bed joint reinforcement is

usually used for in-plane bending elements (like

masonry lintels, walls affected by considerable

deflections of floors) [1-7]. Moreover, it could be used

in places of stress concentration (corners of window

opening) [1, 4-8] and in wall areas under concentrated

loads [6]. Of course, reinforcement is also used in

elements endangered by shrinkage or thermal stresses

[1, 8], or a horizontal load (wind load) [5]. In building

practice, bed joint reinforcement is also used in

buildings with timber floors where it takes over the

stress irregularity from the rim under the wall plate [1,

4-6, 9]. Moreover, bed joint reinforcement is also used

for reducing of scratching [4, 10-11] protecting against

seismic and paraseismic influences [7] and for

improvement of masonry mechanical properties [11].

All the above cases of bed joint reinforcement

application show that it is usually used in elements

loaded mostly vertically. Unfortunately, the research

Corresponding author: Drobiec Lukasz, Ph.D., C.Eng.,

research fields: concrete structures and masonry structures. E-mail: [email protected].

into compressed masonry with the reinforcement

situated in the bed joints comprises only a few levels of

reinforcement percentage. Most investigations concern

unreinforced masonry specimens under compression.

Tests of vertically compressed reinforced masonry

wallettes are presented. Four types of reinforcement in

the form of longitudinal bars and structural wire mesh

were used. The influence of such types of

reinforcement on the load capacity, deformability and

crack resistance was determined. Among other things,

the influence of longitudinal bars as opposed to wire

mesh on the failure form was observed. Measurement

of the strain of the reinforcing bars permitted the

measurement of the strain level at the moment of crack

appearance and also at the moment of failure.

2. Test Models

Investigations were carried out using test specimens

with overall dimensions of 1,265 mm 1,030 mm

250 mm shown in Fig. 1. All elements were built of

clay bricks (with dimensions 65 mm 120 mm 250

mm) and cement-lime mortars 1:1:6 (portland

cement:lime:sand). The depth of mortar joints in

masonry models was 10 mm. Tests included 9 sets of

DAVID PUBLISHING

D

Investigation of Bed Joint Reinforcement Influence on Mechanical Properties of Masonry under Compression

1230

Fig. 1 Test specimen.

the unreinforced masonry specimens marked as “A”

and 24 specimens with 4 types of reinforcement. Two

reinforcement percentages: about 0.1% and about

0.05% were used. The first type of reinforcement was

smooth stainless steel bars with a diameter of 6 mm.

The second was spiral twisted bars of one of the British

systems for protection and strengthening of masonry

fractures, with an outer diameter of about 6 mm. The

series of specimens with smooth bars was marked as

“B” (BI—the reinforcement percentage about 0.05%

and BII with reinforcement percentage 0.1%).

Reinforced series built with using of spiral bars were

marked as “C” (CI and CII). Additionally, two types of

wire mesh, stainless woven wire mesh with bars of

diameter 4 mm (spacing between bars 40 mm 40 mm)

and welded wire mesh from zinc coated steel with the

bars of diameter 1.25 mm and spacing in both

directions 12 mm 12 mm were used. A series of

specimens with wire mesh with 4 mm diameter of bars

was marked as “D” (DI where the reinforcement

percentage is 0.05% and DII where the reinforcement

percentage is 0.1%). Test wallettes with mesh with

1.25 mm diameter welded bars were marked as “E” (EI

where the reinforcement percentage is 0.05% and EII

where the reinforcement percentage is 0.1%). As

reinforcement in FI and FII series were used truss made

from two longitudinal bars 5 mm in diameter and

welded continuous wire diagonal (4.5 mm). In FI series

reinforcement was placed in every 6th bed joint (the

reinforcement percentage was about 0.05%), while in

FII series in every 3rd bed joint (the reinforcement

percentage was about 0.1%). To ensure sufficient

anchorage, flat bars 6 mm 20 mm 40 mm were

welded on the ends of longitudinal rods, and flat bars 6

mm 20 mm 220 mm on the wire mesh ends.

All specimens were loaded during the investigations

in a single cycle. Readings of load level and other

measurements were made every 150 kN. For load force

measurement, a dynamometer was used and for

displacement reading inductive sensors with an

accuracy of 0.002 mm were used. In specimens in the

“B”, “C” and “D” series, the measurement of rod

deformation was made using foil strain gauges—one

gauge in the middle of the length of each steel bar.

Unfortunately, by reason of the bars’ small diameter in

models of the “E” series, it was impossible to use foil

gauges for deformation measurement. Therefore, for

these specimens the steel strains were not measured.

A general view of the test wallette and the inductive

sensor placing is given in Fig. 1. All types of

reinforcement with the strain gauge distribution is

shown in Fig. 2. Simultaneously, material tests of

compressive and tensile strength of the mortar

according to EN 1015 [12] regulations were carried out.

The compressive strength and modulus of elasticity of

bricks to EN 772-1 [13] were also measured. The

tensile strength of reinforcing steel according to Polish

Standard PN-91/H-04310 [14] was measured.

Additionally, using EN 1052-1 [15] the compressive

strength and modulus of elasticity of masonry

specimens were tested.

3. Results of Material Properties Tests

The values of the mortar properties and compressive

strength of bricks are shown in Table 1. The compressive

Fig. 2 Type

Table 1 Mo

Determined v

Compressive

Bending stren

strength of

tensile stren

compressive

In Table 2, t

strength, yie

for smooth

reinforcing b

using extens

In

of models rein

rtar and clay b

alue

strength fm (N/m

ngth fmt (N/mm2

the mortar w

ngth in bendin

e strength of b

the values of

eld point and m

and spiral t

bars strength

someter. The

nvestigation Pro

nforcement.

bricks propert

mm2) 2)

was 7.2 N/m

ng was about

bricks was ab

f ultimate ten

modulus of e

twisted rods

-strain graph

load capacity

of Bed Joint perties of Ma

ties.

M

Value

7.2

2.4

mm2, whereas

t 2.4 N/mm2.

bout 69.7 N/m

sile force, ten

lasticity obta

are given.

was acquired

y of masonry t

Reinforcemeasonry under

Mortar EN 1015

(%

6.6

5.5

s the

The

mm2.

nsile

ained

The

d by

tests

acc

mec

test

4. R

In

com

Poi

ent Influence Compressio

5 [12]

%)

ording to EN

chanical prop

ts are shown i

Results of M

n Table 4, th

mpressive str

sson’s ratio

on Mechanicon

Clay

Value

69.7

-

N 1052-1 [1

perties of the

in Table 3.

Main Inves

he comparison

rength, mod

for all unre

cal

y bricks EN 772

(%

3.8

-

15] were con

e masonry ob

stigations

n of the avera

dulus of elas

einforced an

1231

2-1 [13]

%)

nducted. The

btained in the

age values of

ticity E and

d reinforced

e

e

f

d

d

1232

Table 2 Smo

Determined v

Rip force (kN

Tensile streng

Yield point (N

Modulus of el

Table 3 Mas

Determined v

Compressive

Modulus of el

Poisson’s ratio

Table 4 Com

Determined vseries symbol A

BI

BII

CI

CII

DI

DII

EI

EII

FI

FII

*Percentage o

masonry wa

of unreinforc

about 10%

specimens a

The comp

relationships

In

ooth and spira

alue

N)

gth (N/mm2)

N/mm2)

lasticity (N/mm

sonry properti

alue

stress (N/mm2)

lasticity (N/mm

o

mpressive stren

alue Kind o

-

Smoot

Smoot

Spiral

Spiral

Woven

Woven

Welde

Welde

Truss t

Truss t

f reinforcement

allettes is show

ced specimen

% lower tha

according to R

parison of th

s for all unre

nvestigation Pro

al rod properti

m2)

ies.

m2)

ngth, modulus

of steel

th bars

th bars

twisted bars

twisted bars

n wire mesh

n wire mesh

ed wire mesh

ed wire mesh

type

type

t after outside d

wn. The com

ns is about 14

an obtained

Ref. [15], as s

he resultant s

einforced mo

of Bed Joint perties of Ma

es.

Smooth

Value

23.1

817

760

204,000

value

15.4

12,135

0.23

s of elasticity a

Percentage of armature (%)-

About 0.05

About 0.1

About 0.05*

About 0.1*

About 0.05

About 0.1

About 0.05

About 0.1

About 0.05

About 0.1

diameter.

mpressive stren

.08 N/mm2 an

from stan

shown in Tab

stress-strain (

dels (“A” ser

Reinforcemeasonry under

h rod PN-91/H-

(%

0.9

0.9

0.7

1.2

nd Poisson’s r

f Comprstrengt14.08

16.22

13.98

15.13

13.26

17.30

17.53

19.22

19.83

14.3

17.6

ngth

nd is

dard

ble 3.

(σ-ε)

ries)

and

is s

quit

com

Stan

with

ent Influence Compressio

-04310 [14]

%)

Masonry specim

atio for all test

ressive th (N/mm2)

d masonry spe

shown in Fig

te similar.

mpressive str

ndard) specim

h regard to th

on Mechanicon

Spiral

Value

8.4

970

910

-

men EN 1052-1

(%)

6.9

9.4

6.8

t series.

Modulus of el(N/mm2) 13,910

14,440

14,600

12,250

13,260

12,470

12,180

12,420

13,640

10,779

11,830

ecimens (acco

g. 3. The init

The ultimat

ress is greate

mens. The tan

he σ-ε curve

cal

rod PN-91/H-0

(%

0.8

0.8

0.7

-

1 [15]

asticity Poisson

0.21

0.20

0.23

0.13

0.15

0.15

0.15

0.13

0.13

0.18

0.16

ording to the s

ial part of bo

e (maximum

er for the sm

ngent angle o

for models o

04310 [14]

%)

n’s ratio

standard [15]

oth curves is

m) value of

maller (EC-6

of inclination

of “A” series

])

s

f

6

n

s


1233

decreases more quickly than for the standards’

specimens, where it is nearly stable up to about 85% of

ultimate compressive strength. The graphs of average

values of σ-ε relationships for all test series are shown

in Fig. 4.

5. Analysis

5.1 Models with Longitudinal Bed Joint Reinforcement

The comparison of the compressive strength values

of reinforced wallettes with longitudinal bars with

unreinforced specimens (Table 4) shows that the

increase of strength was only a small percentage for

models of BI and CI series, about 15% and 7.5%,

respectively. However, in models of BII and CII series

(bigger percentage of reinforcement) some decrease of

compressive strength was observed. A more significant

decrease of strength was obtained for spiral twisted bar

reinforced models (CII). The decrease of the

compressive strength of the more strongly reinforced

elements (ρ = 0.1%) is connected with a change in the

form of their failure. In unreinforced models, first

cracks appeared at about 40-50% of the maximum

Fig. 3 The σ-ε relationship for unreinforced models: “A” series and EC-6 masonry standards’ specimens.

Fig. 4 Graphs of average σ-ε relationships for all test series.

0.0000 0.0005 0.0010 0.0015 0.0020 0.0025 0.0030 0.0035 0.0040 0.0045

25.0

20.0

15.0

10.0

5.0

0.0

σ (N

/mm

2 )

18.0

16.0

14.0

12.0

10.0

8.0

6.0

4.0

2.0

0

σ (N

/mm

2 )

0.0000 0.0005 0.0010 0.0015 0.0020 0.0025 0.0030 0.0035


1234

compressive stress. All cracks had a generally vertical

direction. In agreement with Hilsdorf theory, the

masonry units cracked first. Then, as the load increased

the cracks included head joints of the upper and lower

neighbouring brick courses and as a consequence, the

wallette divided into a few separate pillars (Fig. 5a).

Failure of specimens with longitudinal reinforcement

was quite different. All models were split into two

separate leaves by an internal crack (as shown in Fig.

5b). The decrease of strength, which is greater for

reinforced specimens with the smooth bars, is related to

the appearance of the notch effect, which is connected

with a stiff inclusion, in shape of bars, in weak mortar

joints. All elements with the smaller percentage of

reinforcement (BI and CI series) were characterized by

a larger number of cracks, which also had a larger

width than observed in models of BII and CII series. In

models of BII series (ρ = 0.1%) the local spalling of the

masonry surface in the area of bars’ location was

observed.

Some graphs displaying an average stress range

(from the first crack appearance to failure) is presented

in Fig. 6. Elements reinforced with the spiral bars

cracked under greater stress levels than elements

reinforced with smooth steel rods. Cracking of models

reinforced with spiral bars took place with almost the

same stress level as for unreinforced models. The stress

level corresponding with crack appearance of

reinforced models was lower than obtained for

unreinforced specimens. The first crack in reinforced

(using longitudinal bars) models always appeared in a

different place to that in the unreinforced elements.

Graphs of steel deformation in relation to compressive

strength level in the wallettes are presented in Fig. 7.

The first to strain were the spiral rods (larger adherence

of to mortar in joint). The rods in masonry with a

greater percentage of reinforcement (ρ = 0.1%)

stretched earlier. The comparison of the strength of

tensile rods located in the masonry with σt-ε

relationship obtained from the smooth rod tensile tests

are shown in Fig. 8. For smooth rods in the wall with a

percentage about 0.05% (BI series), the level of tensile

stress of 53% of the yield point of steel were obtained.

Whereas for smooth bars in masonry with double that

percentage (about 0.1% in BII series), the level of

tensile stress was about 39% of the yield point of steel.

The designated level of tensile stress in spiral bars was

49% of the yield point of steel for models of CI series

and 30% for CII series. The comparison of both types

of bed joint reinforcement shows that spiral bars are

more effective. That kind of reinforcement combined

better with the mortar in the walls’ joints (Fig. 7) and

(a) (b)

Fig. 5 Typical crack pattern of tested elements: (a) unreinforced and with wire mesh reinforcement; (b) reinforced with longitudinal bars and truss type.


1235

Fig. 6 Graph of stress interval from first crack to failure for all test series.

Fig. 7 Graph of steel deformation in relation to compressive stress level for “B” and “C” series.

Fig. 8 Comparison of σt-ε relationships for rods located in masonry with σt-ε obtained from rod tensile tests.

ρ = 0.05%

ρ = 0.1%

0‰ 5‰ 10‰ 15‰

σ t (

N/m

m2 )

22.020.0

18.0

16.0

14.0

12.0

10.0

8.0

6.0

4.0

2.0

0.0

σ t (

N/m

m2 )

0 0.0005 0.001 0.0015 0.002 0.0025 0.003

ρ = 0.05%

ρ = 0.05%

ρ = 0.1%

ρ = 0.1%

24.022.020.018.016.014.012.010.08.06.04.02.00.0

σ (N

/mm

2 )


1236

did not change the value of modulus of elasticity in

comparison to the unreinforced models (Table 4).

Moreover, it has much better influence on the crack

resistance (Fig. 6). The increase of strength obtained

for models with the lower reinforcement percentage

(CI) towards the elements reinforced with smooth steel

(BI) could be explained by its three times lower area

than the spiral bars. As in case of reinforcement in the

shape of smooth bar (BII), there was found to be some

decreasing of load capacity for series with greater (ρ =

0.1%) reinforced percentage (CII).

5.2 Models with Wire Mesh Reinforcement

Reinforcement in the shape of wire mesh gives a

more significant growth of load capacity in comparison

to reinforcement in the form of longitudinal bars (Table

4). In the case of the lower reinforcement percentage,

the growth of the load capacity for woven wire mesh

reinforcement (DI) was about 23% and for welded wire

mesh (EI) about 37%. Doubling the reinforcement

percentage caused a slight growth of load capacity. For

walls reinforced with the greater percentage of woven

wire mesh (DII), the authors obtained a growth of the

load capacity of over 25% in comparison to the

unreinforced models. For specimens with welded wire

mesh (EII), the load capacity increased even more by

about 41%. The failure shape of tested wallettes was

typical—all specimens were divided by vertical cracks

into a few pillars. It is an identical situation to that

observed for unreinforced models (Fig. 5a). Using a

wire mesh bed joint reinforcement eliminated the

disadvantageous crack pattern which was observed for

elements with longitudinal bar reinforcement. In the

models of “D” series, the failure was connected with

the reinforcement anchorage and vertical cracks in the

anchorage planes. In elements of “E” series, the failure

by a few vertical cracks corresponded with the moment

of breaking the reinforcement (two longitudinal bars).

The wire mesh worked with the masonry much better

than longitudinal bars because the mesh limited the

mortar’s deformation in the whole horizontal plane.

The deformation of longitudinal and lateral bars in the

“DI” models as a function of compressive stress is

shown in Fig. 9. It shows that longitudinal and lateral

bars worked in a similar way. That is why the influence

of the wire mesh longitudinal bars is very important for

masonry strength. The comparison of the deformation

of the longitudinal bars of the “B” and “C” series with

wire mesh longitudinal 4 mm diameter bars (Fig. 9)

shows that the deformation of wire mesh bars is less by

half.

Reinforcement in the form of wire mesh also has a

greater influence on masonry crack resistance. The

limitation of mortar deformation has a significant

Fig. 9 Steel deformations for lateral and longitudinal bars in relation to compressive stress for models of “D” series.

20.0

18.0

16.0

14.0

12.0

10.0

8.0

6.0

4.0

2.0

0.0

σ (N

/mm

2 )

0 0.0002 0.0004 0.0006 0.0008 0.001 0.0012 0.0014 0.0016


1237

influence on the level of stress corresponding with the

first crack appearance (Fig. 6). In the case of the “D”

series, first cracks were observed for a compressive

stress level σc of about 13 N/mm2, whereas the

elements of the “E” series were cracked at σc of about

14.3 N/mm2, a result similar to the unreinforced

elements.

5.3 Models with Truss Type Reinforcement

The comparison of values of the compressive

strength of unreinforced and reinforced F series (Table

4) was found that small percentage of the

reinforcement in FI specimens does not have an effort

on carrying capacity of masonry and the bigger

percentage (FII specimens) increases about 25% of the

strength. Reinforcement reduces masonry modulus of

elasticity and Poisson’s ratio.

Bed joint reinforcement caused the change of

masonry failure. Destruction was always into internal

joint. All models were split into two independent

shields (Fig. 10). There were cut out the reinforcements

from every specimens after finishing the researches. It

was said that the tensile failure was done to the

continuous wire diagonal (Fig. 11), what explains the

cracks along the internal joint.

The results of the measurement of the strains of

reinforcing bars with both percentages showed that the

strains of the longitudinal bars and the continuous wire

diagonal are similar. The tensile failure of the

continuous wire diagonal results from the smaller

diameter. It is clear that using the continuous wire

diagonal with the higher diameter may cause the

increase the crack resistance and compressive strength

of masonry. Fig. 12 are displayed exemplary

reinforcement strains in the function of masonry

compressive strength.

Fig. 10 Failure of FI series models.

Fig. 11 Truss type reinforcement cut out from specimen after finishing the researches.


1238

Fig. 12 Bars steel deformations in relation to compressive stress for models of “F” series.

6. Conclusions

The investigations carried out showed the significant

influence of bed joint reinforcement on the behavior of

masonry wallettes subjected to axial compressive loads.

The analysis of tests results given above leads the

authors to formulate the following conclusions:

(1) Using bed joint reinforcement in the shape of

longitudinal bars (smooth and spiral twisted) is not

very beneficial. For ρ = 0.05% a slight growth of load

capacity in comparison with unreinforced specimens

was determined. Unfortunately, for double the ρ value

(ρ = 0.1%) a decrease of the load capacity was noted;

(2) A very disadvantageous failure shape (dividing

of the wall into two separate leaves) was observed for

specimens reinforced with longitudinal bars and truss

type;

(3) A more positive effect is given by the use of

woven or welded wire mesh bed joint reinforcement.

For reinforcement percentage ρ = 0.05%, about 23%

(woven wire mesh) and about 37% (welded wire mesh)

growth of load capacity with reference to unreinforced

specimens was obtained. Increasing of ρ value (up to ρ

= 0.1%) gave a further slight growth of load capacity;

(4) The failure shape was typically the same as in the

case of unreinforced specimens—dividing the masonry

wallettes by vertical cracks into a few separate pillars;

(5) In models with truss type reinforcement small

reinforcement percentage (ρ = 0.05%) did not effect the

mechanical features of the masonry. Double increase of

the reinforcement (ρ = 0.1%) caused the enlargement

of the capacity (about 25%) and crack resistance (about

23%);

(6) The usage of reinforcement has influence on the

failure of models: limited scratching of front surfaces

of elements and destruction in internal joint.

References

[1] K.J. Schneider, N. Weickenmeier, Present Masonry

Constructions, Werner Verlag GmBH & Co.KG,

Düsseldorf, Berlin, 2000.

[2] J.E. Amrhein, Reinforced Masonry Engineering

Handbook, Clay and Concrete Masonry, Masonry Institute

of America, CRC Press Boca Raton, New York, 1998.

[3] L. Drobiec, About the necessity of using appropriate

reinforcement in the wall bed joint, Monography

Reprocity Resume, Faculty of Civil Engineering, Silesian

University of Technology, Gliwice, 2008, pp. 89-95.

[4] P. Timperman, J.A. Rice, Bed joint reinforcement in

masonry, in: Proceedings of the Fourth International

Masonry Conference, British Masonry Society, London,

1995, pp. 451-453.

[5] O. Pfeffermann, G. van de Loock, 20 Years experience

with bed joint reinforced masonry in Belgium and Europe,

in: Proceedings of the 9th International Brick/Block

Masonry Conference, Berlin, Germany, 1991, pp.

427-436.

[6] P. Schiessl, S. Schmidt, Reinforced masonry—Discussion

about the way of building, Beratende Ingenieure 7 (8)

(1989) 28-31. (in German)

[7] G. van de Loock, Special reinforcement of masonry,

Ziegelindustrie International 1 (1980) 16-18. (in German)

[8] T. Mader, Reinforced masonry in practice bewehrtes

mauerwerk in der praxis, Das Bauzentrum 5 (1993) 65-66.

(in German)

[9] W. Jäger, L. Drobiec, Bed joint reinforced masonry under vertical compression, Mauerwerk 6 (2006) 252-257. (in

16.0

14.0

12.0

10.0

8.0

6.0

4.0

2.0

0.0

σ t (

N/m

m2 )

0 0.0002 0.0004 0.0006 0.0008 0.001 0.0012 0.0014 0.0016 0.0018 0.002


1239

German) [10] R. Pohl, The reinforcement increases the way of using the

brick walls, Das Bauzentrum 9 (1996) 125-128. (in German)

[11] O. Pfeffermann, B. van Hoorickx, Some practicular applications of reinforced masonry in Belgium, in: Proceedings of the 12th International Brick/Block Masonry Conference, Madrid, Spain, 2000, pp. 1437-1446.

[12] BS EN 1015-11:1999, EN 1015 Methods of Test for Mortar for Masonry, British Standards Institution, 1999.

[13] EN 772-1 Methods of Test for Masonry Units—Part 1: Determination of Compressive Strength, 2000.

[14] PN-91/H-04310, Static Tensile Testing of Metals, Polish Code, 1991. (in Polish)

[15] EN 1052-1 Method of Test for Masonry, Determination of Compressive Strength, Brussels, Belgium, 1999.


Evaluating the Effectiveness of Best Management

Practices in Gilgel Gibe Basin Watershed—Ethiopia

Tamene Adugna Demissie1, Fokke Saathoff2, Yilma Seleshi3 and Alemayehu Gebissa2

1. Department of Civil Engineering, Jimma Institute of Tehnology, Jimma University, Jimma 378, Ethiopia

2. Institute for Environmental Engineering, University of Rostock, Rostock 18051, Germany

3. Civil Engineering Department, Addis Ababa Institute of Technology, Addis Ababa University, Addis Ababa 150461, Ethiopia

Abstract: Soil erosion/sedimentation is an immense problem threatening the live storage capacity of dam reservoirs in Ethiopia. This in turn reduces the power generation capacities of hydropower reservoirs. Therefore, studies which give insight into soil erosion/sedimentation mechanisms and mitigation methods is important. The high rate of soil erosion/sedimentation threats the lifespan of Gilgel Gibe-1 hydropower reservoir. The problem of sedimentation in Gilgel Gibe-1 will also affect Gilgel Gibe-2 which uses the water released from Gilgel Gibe-1. The sustainability of these hydropower plants needs catchment management practices that will reduce soil erosion. This paper presents the results of monthly and yearly sediment yield simulations experiments conducted for Gilgel Gibe-1 under different BMP (best management practice) scenarios. The scenarios applied in this paper are: (1) maintaining existing conditions; (2) introducing filter strips; (3) applying stone/soil bunds; (4) reforestation. The SWAT (soil and water assessment tool) was used to model soil erosion, identify soil erosion prone areas and assess the impact of BMPs on sediment reduction via simulations. The simulation results showed that applying filter strips, stone bunds and reforestation scenarios could reduce the current sediment yields at soil erosion prone areas and at the outlet of the catchment area which is the inlet to Gilgel Gibe-1 reservoir. Key words: BMPs, SWAT, sedimentation.

1. Introduction

The Gilgel Gibe River is a right hand tributary of

one of the eight major river basins in Ethiopia, the

Omo-Gibe river basin. It is the major source of water

for Gilgel Gibe dam reservoir project which has a live

storage capacity of 657 Mm3. But the storage volume

of this reservoir is threatened by the soil erosion and

subsequent sedimentation from the upstream of the

Gilgel Gibe basin. Previous studies indicate that there

is a rapid loss of storage volume due to excessive soil

erosion and subsequent sedimentation in Gilgel

Gibe-1 dam reservoir. Devi et al. [1] conducted a

cross sectional study and assessed the siltation and

nutrient enrichment level of Gilgel Gibe-1 dam

reservoir. From their study, they found that siltation

Corresponding author: Tamene Adugna Demissie, M.Sc.,

research fields: water resources management and watershed modeling. E-mail: [email protected].

and nutrient enrichment were the major problems in

this reservoir.

In addition to Gilgel Gibe-1 hydropower plant, the

power generation of the Cascade hydropower plant to

Gilgel Gibe-1, namely Gilgel Gibe-2 Which has an

installed capacity of 420 MW and uses the water

released from the same reservoir, will significantly be

affected.

Currently, the government of Ethiopia is

constructing a huge hydropower plant, Gilgel Gibe-3,

downstream of Gilgel Gibe-1 and 2. The Gilgel

Gibe-3 dam and powerhouse are being built

approximately 155 km downstream of the Gilgel

Gibe-2 plant. Up on its completion Gilgel Gibe-3 will

have an installed capacity of 1,870 MW. There is also

a plan to construct Gilgel Gibe-4 which will be the

farthest downstream in the cascade. Though the

Government of Ethiopia is putting an effort to

DAVID PUBLISHING

D

Evaluating the Effectiveness of Best Management Practices in Gilgel Gibe Basin Watershed—Ethiopia

1241

construct large hydropower plants to supply the

energy demand of the country, the rapid loss of

storage volume due to sedimentation is major problem

of all reservoirs. Some preliminary studies indicate

that the levels of some reservoirs (e.g., Koka

reservoir), lakes (e.g., Alemaya, Awassa, Abaya and

Langano) have decreased. The process is so

challenging that the initial water carrying capacity the

dams has reduced due to progressive silt accumulation.

For example, the Koka dam has accumulated about

3.5 million m3 of silt (or 2,300 t·km-2) in just 23 years

[2]. Thus, an insight into the soil

erosion/sedimentation mechanisms and the mitigation

measures plays an indispensable role for the

sustainability of the existing reservoirs and newly

planned projects. To develop effective soil erosion

control mechanisms through watershed development

programs and to achieve reductions in sedimentation,

it is necessary to quantify the sediment yield and

identify areas that are highly vulnerable to erosion.

Literature review shows that there are many

catchment models that include the soil

erosion/sedimentation processes and simulate the

effect of mitigation measures [3, 4]. The range of

models can be viewed in the way they represent the

area to which they are applied, that is, whether the

model considers processes and parameters to be

lumped or distribute. With increasing computing

power over the last two decades, distributed

approaches have become more feasible. Distributed

models reflect the spatial variability of processes and

outputs in the catchment analysis. A distributed

approach seems particularly applicable to sediment

transport modelling [4]. Some of the soil erosion

models are AGNPS (agricultural non-point source

pollution model) [5], ANSWERS (areal nonpoint

source watershed environmental response simulation)

[6], CREAMS (chemicals, runoff and erosion from

agricultural management systems) [7], EPIC (erosion

productivity impact calculator) [8], EROSION-3D [9],

EUROSEM (European soil erosion model) [10],

SWAT (soil and water assessment tool) [11], WEPP

(water erosion prediction project) [12], and so on.

However, there are a few applications of erosion

modelling in Ethiopia and most of them concentrate

on Blue Nile basin. In the Blue Nile Basin [13]

simulated soil loss in the Dembecha catchment using

WEPP, Haregeweyn and Yohannes [14] applied

AGNPS and predicted sediment yield in Augucho

catchment. The same AGNPS model was used by Ref.

[15] to simulate sediment yield in the kori catchment.

Hengsdijk et al. [16] applied LISEM (limburg soil

erosion model) to simulate effect of reforestation on

soil erosion in the Kushet—Gobo Deguat catchment.

Steenhuis et al. [17] calibrated and validated a simple

soil erosion model in the Abbay (Upper Blue Nile)

basin and obtained a reasonable result, and Setegn et

al. [18] applied SWAT for simulation of a sediment

yield in the Anjeni gauged catchment and obtained

quite acceptable result. SWAT has been successfully

applied by different researchers in Ethiopia. Most of

the SWAT model applications in Ethiopia concentrate

on the Blue Nile river basin. For instance,

Tesfahunegn et al. [19] applied SWAT model to

evaluate the effectiveness of different scenarios in

reducing runoff, sediment and soil nutrient losses in

northern Ethiopia. Asres and Awulachew [20] applied

the SWAT model to establish the spatial distribution

of sediment yield and to test the potential of watershed

management measures to reduce sediment loading

from hot spot areas in Gumara watershed (Blue Nile)

and Betrie et al. [21] also applied the SWAT model to

assess the impact of BMPs on sediment reductions in

the Upper Blue Nile River Basin. Though the SWAT

model is widely applied in Ethiopia, particularly on

the Blue Nile river basin, there is no literature that

indicates the SWAT model application on Omo-Gibe

basin in general and Gilgel Gibe-1 basin in particular.

In this study, the SWAT model has been applied to the

Gilgel Gibe river basin with specific focus on BMPs

application. Currently, there is a recommendation to

protect the buffer zone around Gilgel Gibe-1 dam


1242

reservoir from agricultural practices. In addition to the

buffer zone protection, the Oromiya Environmental

Protection Bureau is also implementing watershed

development through the community based

participatory approach of Ref. [22] management

practices to reduce soil erosion and conserve soil and

water under its basin development programme. Such

basin development programme should be aided by

powerful modelling tools such as SWAT. Therefore,

the objective of this study is to model the spatially

distributed soil erosion/sedimentation process in the

Gilgel Gibe basin at monthly and yearly time steps

and assess the impact of different catchment

management interventions applied on hot spot areas

on sediment yield. A brief description of the Gilgel

Gibe basin is given in the next section, followed by a

discussion on the methodology used. The third section

presents the model results and discussion of different

land management scenarios. Finally, the conclusion

summarizes the main findings of the investigations.

2. Description of the Study Area

As it is indicated in Fig. 1, the Gilgel Gibe-1

watershed is situated in the south-western part of

Ethiopia. The project is purely a hydropower scheme,

with an installed capacity of 180 Mw, aimed to

increase energy and power supply to the national grid.

The reservoir has a live storage capacity of 657 mm3.

The catchment area of the Gilgel Gibe basin is about

5,125 km2 at its confluence with the great Gibe River

and about 4,225 km2 at the dam site. The basin is

generally characterized by high relief hills and

mountains with an average elevation of about 1,700 m

above mean sea level. The basin is largely comprises

of cultivated land. In general terms, the Gilgel Gibe

basin is characterized by wet climate with an average

annual rainfall of about 1,550 mm and average

temperature of 19 oC. The seasonal rainfall

distribution takes a uni-modal pattern with maximum

during summer and minimum during winter,

influenced by the ITCZ (inter-tropical convergence

zone).

3. Methodology

3.1 SWAT Model Description

The SWAT is a physical process based model to

Fig. 1 Location map of the Gilgel Gibe-1 watershed.


1243

simulate continuous time landscape processes at a

catchment scale [11, 21, 23]. The catchment is divided

into HRU (hydrological response units) based on soil

type, land use and slope classes. The major model

components include hydrology, weather, soil erosion,

nutrients, soil temperature, crop growth, pesticides

agricultural management and stream routing. The

model predicts the hydrology at each HRU using the

water balance equation, which includes daily

precipitation, runoff, evapo-transpiration, and

percolation and return flow components. The SWAT

model has two options for computing surface runoff:

(1) the Natural Resources Conservation Service CN

(Curve Number) method [24]; or (2) the Green-Ampt

method [25]. The flow routing in the river channels is

computed using the variable storage coefficient

method [26], or Muskingum method [27]. SWAT

includes three methods for estimating potential

evapo-transpiration: (1) Priestley-Taylor [28]; (2)

Penman-Monteith [29]; (3) Hargreaves [30]. The

SWAT model employs the MUSLE (modified

universal equations) to compute HRUs level soil

erosion. It uses runoff energy to detach and transport

sediment [31]. The sediment routing in the channel

[32] consists of channel degradation using stream

power [33] and deposition in channel using fall

velocity. Channel degradation adjusted using USLE

soil erodibility and channel cover factors.

3.2 SWAT Model Setup

SWAT model inputs are DEM (digital elevation

model), land use map, soil map and weather data.

There is a considerable amount of data available on

the web, and Map Window SWAT used in this study

used this advantage. MWSWAT (Map Window

SWAT) is delivered along with the following data

[34]: DEM maps: SRTM project [35]; Land: Global

Land Cover characterization [36]; Soil maps: FAO

(Food and Agricultural Organization) [37]. The Step

by Step Geo-Processing & Set up of the Map window

interface for SWAT (MWSWAT) documents [38, 39],

have been followed to extract the required watershed

data and to set up the SWAT model for Gilgel Gibe

basin. The DEM was used to delineate the catchment

and provide topographic parameters such as overland

slope and slope length for each sub-basin. The

catchment area of the Gilgel Gibe was delineated and

discretized into 51 sub-basins using a 90 m DEM [40]

through an MWSWAT interface. The Land use data

which has been constructed from the USGS Global

Land Cover Characterization (GLCC) database [41],

by Abbaspour is used. This map has a spatial

resolution of 1 km and 24 classes of land use

representation. The parameterization of the land use

classes (e.g., leaf area index, maximum stomatal

conductance, and maximum root depth, optimal and

minimum temperature for plant growth) is based on

the available SWAT land use classes. The land cover

classes derived are CRDY (dry land Cropland and

pasture), 36.68%, Gras (Grassland), 15.56%, SAVA

(Savanna) 14.45%, FOEB (evergreen forest) 22.65%,

FOMI (mixed forest) 9.92% and CRWO

(Cropland/woodland mosaic), 0.74%. The soil map

was produced by the Food and Agriculture

Organization of the United Nations [42]. Almost

5,000 soil types at a spatial resolution of 10 km with

soil properties for two layers (0-30) cm and 30-100

cm depth) are provided. Further soil properties (e.g.,

particle-size distribution, bulk density, organic carbon

content, available water capacity, and saturated

hydraulic conductivity) were obtained from Ref. [43].

The soil data is also available from the Water Base

web site [44], and was extracted for the study area.

FAO soil and the slope class maps were overlaid

together to derive 410 unique HRUs. Although the

SWAT model provides an option to reduce the

number of HRUs in order to enhance the computation

time required for the simulation, we considered all of

the HRUs with land use of dry land, cropland and

pasture of to evaluate the management intervention

impact. The daily precipitation, maximum and

minimum temperature, wind speed, average relative


1244

humidity data from Jimma and Sekoru stations were

used to run the model. In addition, as Jimma and

Sekoru meteorological stations have daily data on

duration of sunshine hours, the Angstrom formula

which relates solar radiation to extraterrestrial

radiation and relative sunshine duration is used to

estimate the daily solar radiation to be used in the

model. The missed sunshine data were filled by

non-linear regression analysis with other auxiliary

climate variables such as relative humidity and

temperature data before it was used to estimate solar

radiation. The solar radiation data is required by

SWAT and if not supplied SWAT generates this data.

Though all the daily weather data which are required

to run the model have been supplied, the weather

generator file was also prepared using the 20 years

daily data from these two stations and included in the

project file. Daily river flow data measured at

Asendabo gauging station was used for model

calibration and validation. The flow observations were

available throughout the year, but the sediment

concentration data was not available for Gilgel Gibe

basin. The model was run using daily data of 26 years.

The daily meteorological data from 1980 to 2005 was

used to run the model. The three years data from 1980

to 1982 was used to warm up the model. Whereas, the

data from 1983 to 1992 was used to calibrate the

model and the data from 1993 to 2000 was used to

validate the model. The modeling period selection

considered discharge data quality and availability. A

daily flow was used to calibrate and validate the

model at Asendabo gauging station and sediment

discharge was simulated at the outlet of the Gilgel

Gibe watershed which is in turn an inlet to the Gilgel

Gibe-1 hydropower reservoir. Sensitivity analysis was

carried out to identify the most sensitive parameters

for model calibration using LH-OAT

(One-factor-At-a-Time), an automatic sensitivity

analysis tool implemented in SWAT 2005. SWAT

2005 editor is used to read the project database

generated by Map Window SWAT interface to edit

SWAT input files, execute SWAT, and perform

sensitivity, auto calibration and uncertainty analysis.

Based on the sensitivity analysis results, we identified

8 parameters of interest for this basin. We started with

all 27 hydrological flow related parameters and ranked

by their order of sensitivity in simulating the basin

hydrology. It resulted in about 8 parameters as the

most sensitive ones for this basin. Followed by the

sensitivity analysis, the most sensitive parameters

were calibrated by both manual calibration (expert)

and automatic calibration. Appropriate lower and

upper ranges in parameter values have been assigned

prior to initiating the auto calibration process.

3.3 Model Performance Evaluation

Model evaluation is an essential measure to verify

the robustness of the model. In this study, the

following methods were used: (1) NSE

(Nash-Sutcliffe efficiency); (2) PBIAS (percent bias);

(3) correlation between observed and simulated flows.

The NSE (Nash-Sutcliffe efficiency) is computed as

the ratio of residual variance to measured data

variances [45]. The NSE simulation coefficient

indicates how well the plot of observed versus

simulated values fits the 1:1 line. The Nash-Sutcliffe

is calculated using Eq. (1):

n

i

meanobsi

n

i

simi

obsi

QQ

QQNSE

1

2

1

2

)(

)(1 (1)

where,

obsiQ observed stream flow in m3/s;

simiQ simulated stream flow in m3/s;

meanQ mean of n values;

simmeanQ mean of simulated values;

obsmeanQ mean of observed values;

n =number of observations.

The NSE can range from to +1, with 1 being

a perfect agreement between the model and real

(observed) data. The simulation results were


1245

considered to be good if NSE ≥ 0.75, and satisfactory

if 0.36 ≤ NSE ≤ 0.75 [46]. The PBIAS (percent bias)

measure the average tendency of the simulated data to

be larger or smaller than their observed counterparts. A

positive value indicates a model bias toward

underestimation, whereas a negative value indicates a

bias toward overestimation [47]. The PBIAS < ±25% is

satisfactory [48]. The PBIAS is calculated with Eq. (2).

n

i

obsi

n

i

simi

obsi

Q

QQPBIAS

1

1

)(

100)( (2)

The coefficient of determination R2 value is an

indicator of the strength of the linear relationship

between the observed and simulated values. It ranges

from 0.0 to 1.0, with higher values indicating better

agreement. The R2 is calculated with Eq. (3).

n

i

n

i

obsmean

obsi

simmean

simi

n

i

obsmean

obsi

simmean

simi

QQQQ

QQQQ

R

1 1

22

2

12

)()(

)(( (3)

3.4 Catchment Management Intervention Scenarios

Agricultural conservation practices, often called

best management practices or BMPs, are widely used

as effective measures for preventing or minimizing

pollution from nonpoint sources within agricultural

watersheds. SWAT already has an established method

for modeling several agricultural practices including

changes in fertilizer and pesticide application, tillage

operations, crop rotation, dams, wetlands and ponds.

The model also has the capacity to represent many

other commonly used practices in agricultural fields

through alteration of its input parameters [49]. Ten

important agricultural conservation practices were

selected for representation with the SWAT 2005

model and a number of previous modeling studies

have used SWAT to evaluate conservation practices

around the globe [50]. However, selection of BMPs

and their parameter values are site specific and should

reflect the study area reality [21]. For this study, we

selected BMPs based on the previous traditional soil

and water conservation practices on Ethiopian

highlands. Currently, some of these practices are

largely under implementation through community

based participatory watershed development of Ref.

[45], Ethiopia. The baseline values for the input

parameters could be selected by: (1) a model

calibration procedure; or (2) a “suggested” value

obtained from the literature, previous studies in the

study area, or prior experience of the analyst [50]. For

this study, the baseline values which will represent the

basin existing condition (Scenario 0) for the input

parameters have been selected based on the suggested

value obtained from the literature. For Scenarios 1 and

Scenario 2, the BMPs were represented in SWAT

model by modifying the SWAT parameters to reflect the

effect the practice has on the processes simulated within

SWAT [49]. The scenarios simulated and representation

of BMPs in the SWAT are depicted in Table 1.

Table 1 Scenario description and SWAT parameters used to represent BMPs.

Scenarios Description of BMP SWAT parameter used

Parameter name Input file PRE BMP/Calibration value Post-BMP/Modified value

Scenario 0 Baseline

Scenario 1 Filter strip FILTERW 0 0 1 m

Scenario 2 Stone/soil bund

SLSUB 0-10% 30 m 17.5 m*

BSN 10-20% 30 m 11 m*

20-260% 30 m 10min***

CN2 ** **

USLE_P 1.0 0.5

Scenario 3 Reforestation **** **** *The average values taken from Community Based Participatory Watershed Development Guideline; **The calibration value for discharge is maintained; min***minimum value of SLSUBBSN in SWAT model; ****assigned by SWAT model.


1246

In Scenario 1, filter strips were placed on all CRDY

(dry land, cropland and pasture), all soil types and

slope classes. The effect of filter strip is to reduce

sediment, dissolved contaminants and sediment

adsorbed organics in runoff [51]. Appropriate model

parameter for representation of the effect of filter

strips is FILTERW (width of filter strip). The filter

width value, FILTERW, of 1 m was assigned to

simulate the impact of filter strips on sediment

trapping. The FILTERW value was assigned based on

local research experiences in the Ethiopian highlands

[52, 53]. In Scenario 2, stone/soil bunds were placed

on all CRDY (dry land cropland and pasture), all soil

types and slope classes. This practice has a function to

reduce overland flow, sheet erosion and reduce slope

length [49]. This BMP was selected as it was the

most widely and most intensively used soil

conservation practice in the area [54]. Appropriate

parameters for representing the effect of stone bunds

are the CN (curve number), average slope length

(SLSUBBSN) and the USLE_P support practice

factor (USLE_P). The SWAT assigned value of the

USLE_P value of 1.0 is used prior to the application

of BMPs. The modified value/Post-BMP value for

USLE_P of 0.5 was assigned based on Ref. [52] being

the P factor recommended for all types of bunds in

Ethiopia. The average slope length (SLSUBBSN) for

slopes 0-10% and 10%-20% is taken from the

community based participatory watershed

development guideline which is currently under

implementation in Ethiopian highlands. The minimum

acceptable SLSUBBSN by SWAT is model 10 m and

this value is assigned for slopes greater than 20%. In

Scenario 3, we simulated the impact of reforestation

on sheet erosion. The reforestation has a function to

reduce over land flow and rainfall erosivity. The

reforestation effect was simulated by introducing land

use change. Thus we replaced 1.0% of the area

occupied by CRDY (dry land cropland and pasture) in

to evergreen forest.

4. Results and Discussion

4.1 Model Calibration and Validation

The most sensitive parameters for flow predictions

were CN2 (curve number), ALPHA_BF (baseflow

alpha factor), GW_DELAY (groundwater delay time),

GW_REVAP (ground water “re-vap” co-efficient),

REVAPMN (threshold water depth in the shallow

aquifer for “revap”), ESCO (soil evaporation

compensation factor), SOL_AWC (available water

capacity) and CANMX (maximum canopy storage).

Table 2 shows the most sensitive parameters and fitted

values. These flow parameters were adjusted within

the given limits to initiate auto calibration. As

measured data is not available on sediment yield, only

the modeled data has been used to identify the impact

of adjusting a parameter value on some measure of

simulated sediment output. Accordingly, most

sensitive parameters ranked 1 to 3 were USLE_P

(USLE support practice factor), USLE_C (USLE land

cover factor), and Ch_K2, respectively. The

parameters Ch-Cov (channel cover factor), Ch-erod

(channel erodibility factor), exponent of

re-entrainment parameter for channel sediment routing

(spexp) and linear re-entrainment parameter for

channel sediment routing (spcon) were equally

important with rank 8. The SWAT flow predictions

were calibrated against daily and monthly average

flows with a warm up period of three years from 1983

to 1992 and validated from 1993 to 2002 at Asendabo

gauging station, as shown in Figs. 2 and 3. The

simulated daily flow matched the observed values for

calibration period with NSE, PBIAS and R2 equal to

0.684, -13.9% and 0.726, respectively. For the

validation period, and the observed daily flows

showed acceptable agreement as indicated by NSE,

PBIAS and R2 values equal to 0.640, -5.2% and 0.662,

respectively.

The simulated monthly average flow values also

matched the observed values for calibration period

with NSE and R2 values equal to 0.54 and 0.886,


1247

Fig. 2 Observed and simulated daily hydrographs at Asendabo Station: (a) calibration; (b) validation.

respectively. The calibration parameters were checked

for the validation period and found to be 0.629 and

0.696 for NSE and R2, respectively.

The model simulated well the discharge on the

rising limb of the hydrograph. While, the falling limb

of the hydrograph indicated that the simulated

discharge is slightly greater than the observed

discharge data for the whole calibration and validation

period, and the crest segment of the hydrograph show

the simulated peak discharge to be slightly less than

the observed peak discharge. Generally, as it was

shown by model performance evaluation criteria, the

SWAT model performed well in simulating stream

flow hydrograph for this study. Besides, the

performance of SWAT model, Ndomba and

Griensven [55] indicated that the SWAT model can

satisfactorily estimate sediment yield for even poorly

gauged catchments of East African countries.

4.2 Scenario Analysis

The assessment of the spatial variability of soil

erosion is useful for catchment management planning

[12]. The soil erosion prone areas in the Gilgel Gibe-1

basin are shown in Fig. 4 The SWAT model

simulation shows erosion extent varies from

negligible erosion to 39 t/ha. Based on the

classification of erosion rates in the Ethiopian

highlands [56] the erosion level which are classified as

high and very high in sub-basin 1, 3, 5 and 8 of Gilgel

Gibe-1 basin corresponds to moderate erosion level

(20-70 t/ha/yr). The erosion level in the sub basin 1, 3,

5, and 8 is in the range of 20 t/ha to the maximum

value of 39 t/ha. The erosion level which are indicated

as medium in sub-basins-2, 38 and 46 are relative to

0

50

100

150

200

250

300

19

83

/00

11

98

3/0

81

19

83

/16

11

98

3/2

41

19

83

/32

11

98

4/0

36

19

84

/11

61

98

4/1

96

19

84

/27

61

98

4/3

56

19

85

/07

01

98

5/1

50

19

85

/23

01

98

5/3

10

19

86

/02

51

98

6/1

05

19

86

/18

51

98

6/2

65

19

86

/34

51

98

7/0

60

19

87

/14

01

98

7/2

20

19

87

/30

01

98

8/0

15

19

88

/09

51

98

8/1

75

19

88

/25

51

98

8/3

35

19

89

/04

91

98

9/1

29

19

89

/20

91

98

9/2

89

19

90

/00

41

99

0/0

84

19

90

/16

41

99

0/2

44

19

90

/32

41

99

1/0

39

19

91

/11

91

99

1/1

99

19

91

/27

91

99

1/3

59

19

92

/07

41

99

2/1

54

19

92

/23

41

99

2/3

14

Dis

char

ge(m

3/s

)

Year/day

Daily discharge calibration at Asendabo gauging station

observed

simulated

0

50

100

150

200

250

300

350

400

19

93

/00

1

19

93

/08

1

19

93

/16

1

19

93

/24

1

19

93

/32

1

19

94

/03

6

19

94

/11

6

19

94

/19

6

19

94

/27

6

19

94

/35

6

19

95

/07

1

19

95

/15

1

19

95

/23

1

19

95

/31

1

19

96

/02

6

19

96

/10

6

19

96

/18

6

19

96

/26

6

19

96

/34

6

19

97

/06

0

19

97

/14

0

19

97

/22

0

19

97

/30

0

19

98

/01

5

19

98

/09

5

19

98

/17

5

19

98

/25

5

19

98

/33

5

19

99

/05

0

19

99

/13

0

19

99

/21

0

19

99

/29

0

20

00

/00

5

20

00

/08

5

20

00

/16

5

20

00

/24

5

20

00

/32

5Year/day

Daily discharge validation at Asendabo gauging station

observed

simulated

(a)

(b)

Dis

char

ge(m

3 /s)


1248

(b)

Fig. 3 Observed and simulated monthly hydrographs at Asendabo Station: (a) calibration; (b) validation.

Table 2 SWAT sensitive parameters and fitted values.

Parameter name Description Parameter value

m-CN2.mgt* Curve number 0.8

a-ALPHA_BF.gw** Base flow alpha factor 0.302

r-GW_DELAY.gw Groundwater delay time 45

r-GW_REVAP.gw Groundwater revap co-efficient 0.20

r-REVAPMN.gw Threshold water depth in the shallow aquifer for revap 0.15

r-ESCO.hru Soil evaporation compensation factor 0.25

m-SOL_AWC.sol Available water capacity 1.67

a-CANMX.hru Maximum canopy storage 4

*The extension (e.g., .mgt) refers to the SWAT input file where the parameter occurs; **The qualifier (a-) refers to the substitution of a parameter by adding the parameter values indicated in Table 2 and (m-) refers to the relative change in the parameter where the value from the SWAT database is multiplied by the values in the table. And (r-) refers to replacement in the parameter from the SWAT database by the values indicated in the table.

remaining sub-basins and their erosion level is in the

range of 10 t/ha to 20 t/ha. Generally, the SWAT

simulation results for Gilgel Gibe-1 basin indicate that

the sub-basins 1, 2, 3, 5, 8, 38 and 46 have the high

rate of erosion relative to the remaining sub-basins.

The sub-basins with high rate of erosion have a

maximum percentage of nearly 60% land-use of

CRDY (dry land cropland and pasture) while the

sub-basins with very low soil erosion rate have got

0-9% dry land, cropland and pasture as their landuse.

0

50

100

150

200

Dis

char

ge(m

3 /s)

Year/Month

Monthly discharge calibration at Asendabo Gauging station

observed

simulated

0

20

40

60

80

100

120

140

160

180

200

1993\1

1993\3

1993\5

1993\7

1993\9

1993\11

1994\1

1994\3

1994\5

1994\7

1994\9

1994\11

1995\1

1995\3

1995\5

1995\7

1995\9

1995\11

1996\1

1996\3

1996\5

1996\7

1996\9

1996\11

1997\1

1997\3

1997\5

1997\7

1997\9

1997\11

1998\1

1998\3

1998\5

1998\7

1998\9

1998\11

1999\1

1999\3

1999\5

1999\7

1999\9

1999\11

2000\1

2000\3

2000\5

2000\7

2000\9

2000\11

Discharge(m3/s)

Year/month

Monthly discharge Validation at Asendabo gauging station

observed

Simulated

(a)


1249

These simulation results show the relative variations

of soil erosion level within a sub-basin. These results

are helpful to prioritize BMPs implementation area.

Moreover, these results showed that the sediment

yield to Gilgel Gibe-1 reservoir is mainly from

sub-basins of the tributaries of Nedhi, and Bulbul

which are to the left side of Gilgel Gibe River and at a

close proximity to the reservoir.

The SWAT model simulation for the existing

condition predicted the sediment yield at the outlet of

Gilgel Gibe-1 basin, which is an inlet to Gilgel Gibe

dam reservoir to be 122.73 × 103 t/yr. However,

running the model with different catchment

management scenarios provided interesting results.

The simulation of filter strips scenario reduced the

total sediment yield to 79.82 × 103 t/yr from current

condition at the same outlet location, which is

equivalent to 35% reduction. The simulation of

stone/soil bunds reduced the sediment yield to 23.26 ×

103 t/yr from the current conditions, which is

equivalent to 81% reduction. This result is comparable

to the results reported in the literature. Herweg and

Luid [53] reported 72%-100% sediment yield

reductions by stone bunds at plot scale in Ethiopian

and the Eritrean highlands. The simulation of

reforestation scenario (Scenario 3) showed the average

reduction of sediment yield by 9.1% for sub-basins 1,

3, 5, 8, 2, 38 and 46 from the current condition. This

less sediment reduction under Scenario 3 as compared

to Scenario 1 and 2 could be attributed to smaller

implementation area. The average sediment reduction

at sub-basin level where the sub-basin has got dry land

CRDY greater than 10% of its total area under filter

strip scenario was 35%. This is comparable with

results reported by Betrie et al. [21]. They reported the

sediment reductions under filter strip scenario ranged

from 29% to 68%. In this study, the percentage

sediment yield reduction per ha at sub-basin level

increased with an increase in the percentage area of

CRDY which was provided with filter strip width of 1

m. The sub-basins such as sub-basins 15, 16, 23, 48

and 50 with percentage area of dry land, CRDY

(cropland and pasture) less than 10% showed the

sediment yield reduction efficiency of 0% under

filter strip scenario. The effectiveness of BMPs per

hectare for the sub-basins with different percentage

of dry land, CRDY (cropland and pasture) is shown

in Fig. 5.

Fig. 4 Erosion prone areas in Gilgel Gibe basin.

±

0 19,000 38,0009,500 Meters

Legend

SYLDsc0

<all other values>

Erosion

High

Low

Medium

V.High


1250

Fig. 5 Percentage of CRDY in the subbasin and sediment reduction efficiency of Scenarios 1 and 2.

5. Conclusions

The SWAT model was applied to assess the impact

of the three BMPs (best management practices)

scenarios on sediment reduction in the Gilgel Gibe

river basin. The impact of further subdivision of the

sub-basins in to more number of HRUs on the

effectiveness of BMPs on sediment reduction was also

checked. The model showed that the erosion prone

areas at sub-basin level, which is useful information

for catchment management planning and for the

implementation of the watershed development

program. The watershed development program

through community based participatory approach

under implementation throughout the country. This

study result showed that the implementation of the

three BMPs could reduce the soil erosion and

sediment yield at the sub-basin and basin level. One of

the three BMPs, namely soil/stone bunds has been

practiced and implemented in some of the districts in

the study watershed. The same practice is widely

under implementation in Gilgel Gibe basin as per the

decision made by the Ethiopian Government to

promote and expand community watershed

development in the country. However, the cost of

implementing the BMPs should be evaluated.

Additional BMPs should also be investigated and the

best ones combined to form other scenarios which

reduce soil erosion and sedimentation. This study

shows as the modeling approach could be helpful for

decision makers to prioritize the areas of intervention.

In order to obtain a better estimate of the effectiveness

of the filter strips, further investigation should be

undertaken by using the improved VFS (vegetative

filter strip) sub-model of SWAT 2009 version.

Furthermore, SWAT 2009_LUC, a tool to activate the

land use change module in SWAT 2009 should be

applied for further investigations.

References

[1] R. Devi, T. Subalewu, L. Worku, L. Bishaw, B. Abebe, Assessment of siltation and nutrient enrichment of Gilgel Gibe dam, Southwest Ethiopia, Bio. Resource Technology 99 (2008) 975-979.

[2] E. Gizaw, W. Legesse, A. Haddis, B. Deboch, W. Birke, Assessment of factors contributing to eutrophication of Abasamuel water reservoir in Addis Ababa Ethiopia, Journal of Health Science 14 (2) (2004) 112-113.

[3] D.K. Borah, M. Bera, Watershed-scale hydrologic and nonpoint-source pollution models: Review of mathematical bases, T. ASAE 46 (2003) 1553-1566.

[4] W.S. Merrit, R.A. Letcher, A.J. Jakeman, A review of erosion and sediment transport models, Environ. Modell. softw. 18 (2003) 761-799.

[5] R.A. Young, C.A. Onstad, D.D. Bosch, W.P. Anderson, AGNPS: A non point sourse pollution model for evaluating agricultural watersheds, Journal of Soil and Water Conser-Vation 44 (2) (1989) 168-173.

[6] D.B. Beasley, L.F. Huggins, ANSWERS (Areal Nonpoint Source Watershed Environ-ment Response Simulation): User’s Manual, U.S. Environmental Protection Agency, Chi-cago, Illions, 1982.

0

10

20

30

40

50

60

70

80

90

Percentage reduction

Percentage sediment yield reduction of filter strip and stone bund

AREA(%)

FILTER(%)

STONE BUND(%)


1251

[7] W.G. Knisel, CREAMS: A Field Scale Model for Chemicals, Runoff and Erosion from Agricultural Management Systems, USDA conservation research report, Washington, D.C., 1980.

[8] J.R. Williams, Chapter 25: The EPIC model, in: V.P. Singh (Ed.), Computer Models of Watershed Hydrology, Water Resources Publications, Highlands Ranch, 1995, pp. 909-1000.

[9] J. Schmidt, M.V. Werner, A. Michael, Application of the EROSION 3D model to the CATSOP watershed, The Netherlands, in: A. de Roo (Ed.), Modelling Soil Erosion by Water at the Catchment Scale, Catena, 1999, pp. 449-456.

[10] R.P.C. Morgan, J.N. Quinton, R.E. Smith, G. Govers, J.W.A. Poesen, K. Auerswald, et al., The European soil erosion model (EUROSEM): A dynamic approach for predicting sediment transport from fields and small catchments, Earth Surface Processes and Landforms 23 (6) (1998) 527-544.

[11] J.G. Arnold, R. Srinivasan, R.S. Muttiah, J.R. Williams, Large area hydrologic modelling and assessment Part I: Model development, J. Am. Water Resour. As. 34 (1998) 73-89.

[12] J.M. Laflen, J.L. Lane, G.R. Foster, WEPP (The water erosion prediction project)—A new generation of erosion prediction technology, J. Soil and Water Conserve 46 (1) (1991) 34-38.

[13] G. Zeleke, Landscape Dynamics and Soil Erosion Process Modelling in the North-Western Ethiopian Highlands, in: African Studies Series A, Geographica Bernensia, Berne, 2000.

[14] N. Haregeweyn, F. Yohannes, Testing and evaluation of the agricultural non-point source pollution model (AGNPS) on Augucho catchment, western Hararghe, Ethiopia, Agr. Ecosyst. Environ. 99 (2003) 201-212.

[15] H. Mohammed, F. Yohannes, G. Zeleke, Validation of agricultural non-point source (AGNPS) pollution model in Kori watershed, South Wollo, Ethiopia, Int. J. Appl. Earth. Obs. 6 (2004) 97-109.

[16] H. Hengsdijk, G. Meijerink, M. Mosugu, Modeling the effect of three soil and water conservation practices in Tigray, Ethiopia, Agr. ecosyst. Environ. 105 (2005) 29-40.

[17] T. Steenhuis, A. Collick, Z. Easton, E. Leggesse, H. Bayabil, E. White, et al., Predicting discharge and sediment for the Abay (Blue Nile) with a simple model, Hydrol. Process. 23 (2009) 3728-3737.

[18] S. Setegn, B. Dargahi, R. Srinivasan, A. Melesse, Modeling of sediment yield from Anjeni-Gauged watershed, Ethiopia using SWAT model, Journal of American Water Resources As. 46 (2010) 514-526.

[19] G.B. Tesfahunegn, P.L.G. Vlek, L. Tamene, Management

Strategies for reducing soil degradation through modeling in a GIS environment in northern Ethiopia catchment, Nutrient Cycling in Agroecosystems 92 (2012) 255-272.

[20] M.T. Asres, S.B. Awulachew, SWAT based runoff and sediment yield modeling, a case study of the Gumera watershed in the Blue Nile Basin, Ecohydrology and Hydrobiology 10 (2010) 191-200.

[21] G.D. Betrie, Y.A. Mohamed, A. van Griensven, R. Srinivasan, Sediment management modeling in the Blue Nile Basin using SWAT model, Hydrol. Earth Syst. Sci. 15 (2011) 807-818.

[22] Community Based Participatory Watershed Development, Part 1: A Guideline, MOARD (Ministry of Agriculture and Rural Development), Addis Ababa, Ethiopia, 2005.

[23] S.L. Neitsch, J.G. Arnold, J. Kiniry, J.R. Williams, Soil and Water Assessment Tool Theoretical Documentation (Version 2005), USDA Agricultural Research Services and Texas A & M Blackland Research Center, Temple, Texas, 2005.

[24] National Engineering Handbook, Section IV, Hydrology, USDA-SCS (US Department of Agriculture-Soil Conservation Service, 1972.

[25] W.H. Green, C.A. Ampt, Studies on soil physics: I. Flow of air and water through soils, J. Agr. Sci. 4 (1911) 1-24.

[26] J.R. Williams, Flood routing with variable travel time or variable storage coefficients, T. ASAE 12 (1969) 100-103.

[27] V.T. Chow, Open Channel Hydraulics, McGraw-Hill Book Company, New York, 1959.

[28] C. Priestley, R. Taylor, On the assessment of surface heat flux and evaporation using large-scale parameters, Mon. Weather Rev. 100 (1972) 81-92.

[29] J.L. Monteith, Evaporation and environment, Symp. Soc. Exp. Biol. 19 (1965) 205-234.

[30] G. Hargreaves, G. Hargreaves, J. Riley, Agricultural benefits for Senegal river basin, J. Irrig. Drain. E-ASCE 111 (1985) 113-124.

[31] J. Williams, H. Berndt, Sediment yield prediction based on watershed hydrology, T. ASAE 20 (1977) 1100-1104.

[32] J.G. Arnold, J.R. Williams, D.R. Maidment, Continuous time water and sediment-routing model for large basins, J. Hydraul. Eng-ASCE 121 (1995) 171-183.

[33] J. Williams, SPNM: A model for predicting sediment, Phosphorus, and nitrogen yields from agricultural basins, J. Am. Water. Resour. As. 16 (1980) 843-848.

[34] C. George, L.F. Leon, Water base: SWAT in an open source GIS, The Open Hydrology Journal 2 (2008) 1-6.

[35] A. Jarvis, H.I. Reuter, A. Nelson, E. Guevara, Hole-filled Seamless SRTM Data Version 4, International Centre for Tropical Agriculuture (CIAT), 2008, http://srtm.csi.cgiar.org (accessed Mar. 25, 2012).

[36] M. Hansen, R. DeFries, J. Townshend, R. Sohlberg, 1 km


1252

Land Cover Classification Derived from AVHRR, 1998, http://glcf.umiacs.umd.edu/data/landcover (accessed Apr. 1, 2012).

[37] Digital Soil Map of the World and Derived Soil Properties. Rev. 1. [CD ROM], FAO/UNESCO, 2003, http://www.fao.org/catalog/what_new-e.htm (accessed Apr. 1, 2012).

[38] L.F. Leon, Step by Step Geo-Processing and Set-up of the Required Watershed Data for MWSWAT (Map Window SWAT), Version 2, 2011.

[39] L.F. Leon, Map Window Interface for SWAT (MWSWAT), Version 1.8, 2010.

[40] CGIAR-CSI SRTM 90 m DEM Digital Elevation Database Website, http://srtm.csi.cgiar.org (accessed Apr. 6, 2012).

[41] GLCC (Global Land Cover Characterization) http://edesns17.cr.usgs.gov/glcc/glcc.html (accessed Apr. 1, 2012).

[42] Digital Soil Map of the World and Derived Soil Properties Food and Agricultural Organization of the United Nations, FAO (Food and Agricultural Organization), Rome, 1995.

[43] C.A. Reynolds, T.J. Jackson, W.J. Rawls, Estimated Available Water Content from the FAO Soil Map of the World, Global Soil Profile Databases, and Pedo-transfer Functions, 1999, http://www.ngdc.noaa.gov/seg /cdroms/ reynolds/reynolds/reynolds.htm (accessed Apr. 6, 2012).

[44] Waterbase Website, http://www.waterbase.org/ download (accessed Apr. 4, 2012).

[45] J.E. Nash, J.V. Sutcliffe, River flow forecasting through conceptual models Part I: A discussion of principles, Journal of Hydrolo. 10 (1970) 282-290.

[46] M.W. van Liew, J. Garbrecht, Hydrologic simulation of the little Washita river experimental watershed using SWAT, J. Am. Water Resour. Assoc. 39 (2) (2003) 413-426.

[47] H. Gupta, S. Sorooshian, P. Yapo, Status of automatic calibration for hydrologic models: Comparison with

multilevel expert calibration, J. Hydrol. Eng. 4 (1999) 135-143.

[48] M.W. van Liew, T.L. Veith, D.D. Bosch, J.G. Arnold, Suitability of SWAT for the conservation effects assessment project: Comparison on USDA agricultural research service watersheds, J. Hydrol. Eng. 12 (2) (2007) 173-189.

[49] K. Bracmort, M. Arabi, J. Frankenberger, B. Engel, J. Arnold, Modeling long-term water quality impact of structural BMPs, T. ASABE 49 (2006) 367-374.

[50] M. Arabi, J.R. Frankenberger, B.A. Engel, J.G. Arnold, Representation of agricultural conservation practices with SWAT, Hydrological Processes 22 (16) (2008) 3042-3055.

[51] P. Tuppad, N.K.R. Srinivasan, C.G. Rossi, J.G. Arnold, Simulation of agricultural management alternatives for watershed protection, Water Resour. Manage 24 (12) (2010) 3115-3144.

[52] H. Hurni, Erosion-productivity-conservation systems in Ethiopia, in: Proceedings of the 4th International Conference on Soil Conservation, Maracay, Venezula, 1985, pp. 654-674.

[53] K. Herweg, E. Ludi, The performance of selected soil and water conservation measures—Case studies from Ethiopia and Eritrea, Catena 36 (1999) 99-114.

[54] Y. Anley, A. Bogale, A. Haile-gabriel, Adoption decision and use intensity of soil and water conservation measures by small holder subsistence farmers in Dedo district, western Ethiopia, Land Degrad. Develop. 18 (2006) 289-302.

[55] P.M. Ndomba, A. van Griensven, Suitability of SWAT model for sediment yields modeling in the eastern Africa, advances in data, methods, models and their applications in geoscience, Technical Paper, University of Dares Salam, Dares Salaam, Tanzania, 2011.

[56] H. Hurni, Soil erosion and soil formation in agricultural ecosystems: Ethiopia and Northern Thailand, Mt. Res. Dev. 3 (1983) 131-142.


Performance of a Nonwoven Geotextile Reinforced Wall

with Unsaturated Fine Backfill Soil

Fernando Henrique Martins Portelinha1, Benedito de Souza Bueno2 and Jorge Gabriel Zornberg3

1. Department of Civil Engineering, Federal University of Sao Carlos, Sao Carlos/SP 13564-350, Brazil

2. Sao Carlos Engineering School, University of Sao Paulo, Sao Carlos/SP 13566-536, Brazil

3. Civil Engineering Department, University of Texas at Austin, Austin/TX 78712-0280, USA

Abstract: The use of marginal backfills in GSE (geosynthetic stabilized earth) walls has not been recommended by different standards specifications. Restrictions are motivated by the poor hydraulic conductivity of fine soils that are capable of developing of water pressures. However, the use of granular materials can expend the cost of the construction. As a result, local soils, granular or not, have been increasingly used. Unsaturated conditions of fine soils may result in convenient performance even using extensible reinforcements. This paper evaluates the performance of a full scale model of a nonwoven geotextile reinforced wall constructed with fine grained soil backfill. The unsaturated condition was maintained and matric suctions, displacements and reinforcement strains were monitored during the test. Results have shown that the unsaturated condition of the backfill allowed maximum reinforcement peak strain of 0.4 %. For the case of a wrap faced wall on a firm foundation the performance and good agreement between measured strains and factors of safety from limit equilibrium analyses have shown the maintenance of unsaturated conditions as an economical alternative to the use of high quality fill.

Key words: Reinforced soil wall, nonwoven geotextile, fine soil, unsaturated soil.

1. Introduction

Since the reinforced soil technique began to be used

in retaining walls, embankments and slopes, standard

organizations have been concerned about the

hydraulic behavior of poorly draining backfill soils

[1, 2]. The major problems are the development of

positive water pressures inside the reinforced zone and

reinforcement interaction in the presence of water.

In fact, the low draining capacity of fine soils can

affect the reinforced soil walls performance under

rainfall infiltration as reported by Yoo and Jung [3]

and Fowze et al. [4]. On the other hand, an excellent

performance can be expected from these structures

under unsaturated conditions due to the positive effect

of matric suction on soil and interface behavior.

Khoury et al. [5] report that pullout strength of

Corresponding author: Fernando Henrique Martins Portelinha, Ph.D., research fields: development of concepts, methodologies and tools focused at the geosynthetic technologies applied to geotechnical engineering. E-mail: [email protected].

geotextiles embedded in unsaturated soils are so

influenced by matric suction as shear strength of soils.

Additionally, some real cases reported in the literature

could confirm the strong influence of unsaturated

conditions of backfill on the performance of

geosynthetic reinforced soil walls [6, 7]. The

maintenance of unsaturated conditions of backfill soils

is a difficult task regarding field conditions. Koerner

and Soong [8] recommend avoiding any possible

water in the front, behind and beneath the reinforced

zone collecting, transmitting and discharging the

water. Furthermore, the top of the zone should be

waterproofed, e.g., by a geomembrane or a

geosynthetic clay liner, to prevent water from entering

the backfill zone from the surface. However, Wayne

and Wilcosky [9] reported that use of nonwoven

geotextiles assisted in maintaining fine grained soils

in an unsaturated condition in the reconstruction of

failed slope, since the hydraulic properties of

nonwoven geotextile reinforcements can be useful to

DAVID PUBLISHING

D

Performance of a Nonwoven Geotextile Reinforced Wall with Unsaturated Fine Backfill Soil

1254

dissipate pore water pressures and, consequently,

enhance the internal stability of the structure

[10, 11].

Matric suction can improve the walls performance

in two aspects: increasing the soil stiffness and

improving the interface shear strength behavior.

Therefore, two design implications can be drawn from

these aspects: a stiffer soil favors the selection of

lower stiffness reinforcements, resulting in reductions

of costs; and, convenient interface behavior provides a

good transmission and mobilization of forces by the

reinforcement.

This paper describes the performance of an

instrumented full scale model of a nonwoven

geotextile reinforced soil wall under unsaturated

backfill conditions.

2. Experimental Program

2.1 Materials

Full scale models were constructed using clayey

sand with a hydraulic conductivity of 5 × 10-6 cm/s,

with 40% passing the No. 200 sieve, and low

plasticity (PI = 18%). Compaction parameters from

standard Proctor tests are maximum dry unit weight of

17.8 kN/m3 and optimum water content of 14.6%.

With the relative low hydraulic conductivity and

significant percentages of fine particles, this material

would be restricted from use by AASHTO [2] and

FHWA [1], being classified as a poorly draining soil.

Triaxial tests in unsaturated soil samples indicated

cohesion of 0 kPa and friction angle of 38o for CD

(consolidated drained) tests and, cohesion of 60 kPa

and friction angle of 25o for CU (consolidated

undrained) tests, in terms of total stresses.

The reinforcement consisted of a polyester

needle-punched nonwoven geotextile made of

polyester with a mass per unit area of 293 g/m2,

thickness of 2.69 mm, tensile strength of 10 kN/m and

strain at failure of 83% (testing was performed in

accordance with ASTM D4595). A relatively weak

and extensible geotextile was specifically selected to

generate detectable strain levels.

2.2 Full Scale Model Construction

Full scale walls have been constructed in the

Laboratory of Geosynthetics located within the Sao

Carlos School of Engineering at the University of Sao

Paulo. A metallic box allows reinforced soil wall

structures to be constructed with 1.8 m height by 1.55

m width, with backfill soil extending to a distance of

1.8 m from the front edge of the metallic box. The soil

was compacted at 98% of relative density and the

maximum dry unit weight and optimum water content

from standard Proctor tests. In order to assure the

required relative density, compaction was performed

manually in layers of 5 cm height. Compaction

control was assured by the drive-cylinder method

(ASTM D2937), spiked every compacted layer

reaching 30 cm height. The backfill soil was seated on

a rigid concrete foundation.

Geotextile reinforcements were placed at 30 cm

vertical spacing with declivity of 1% to the face. Each

layer of reinforcement had a total length of 1.80 m

measured from the face. The wall was constructed

with no facing batter and using the wrapped-around

technique. Protective shotcrete coating varying from 5

cm to 8 cm was used. Drainage geocomposites were

used as face drainage elements into the second and

forth reinforced layers located at 30 cm from the face

forward into the wall. Fig. 1 presents the cross section

view of the model.

2.3 Instrumentation

Instrumentation was deployed to record pore water

pressures including negatives values (soil suction),

internal horizontal displacements, reinforcement

strains and horizontal face displacements. Instruments

locations are presented in Fig. 2.

Matric suction was monitored by tensiometers

(range of -100 kPa to 100 kPa) located in the middle

of each reinforced layer at 5 cm above the

reinforcements at a distance of 80 cm and 140 cm

from the face.


1255

Shotcretefacing

Facing drains

Airbag

Reaction lid

Acquisitionsystem

Base layer

1

Steel beam

165

160

Drainagegeocomposites

Reinforcement layers

Concrete

Soil

Shotcrete facing

i=1%

1

2

3

4

5

(cm) 180

(a) Frontal photograph (b) Cross section

Fig. 1 Geotextile reinforced soil wall model.

Base layer

Reinforcement layers

Concrete

Soil

Tensiometer

Water content sensor

Tell tailsDial indicators

Earth pressure cellsTensiometers

INSTRUMENTS

Fig. 2 Instruments location.

Internal displacements were measured by tell-tales.

These devices consisted of stainless steel inextensible

wires, which run inside of plastic tubes used to reduce

friction and to protect the wires. One end of the

tell-tales is fixed to the geotextile and the opposite is

connected to a small weight that is used to tension the

wires and to obtain measures. Relative displacements

between the weight and a reference located in a shaft

behind the wall were measured during the test.

Tell-tales were fixed at five points along

reinforcements at 30 cm of horizontal spacing.

Other displacement instruments were used in this

research but they will not be assessed in this paper.

2.4 Test Procedure

The test procedure involved recording of

instrumentation incorporated within the full scale

model under a uniform loading of 100 kPa.

Instrumentation records were maintained from the

beginning of construction and throughout the initial

90 days of loading.

3. Results

3.1 Instrumentation Results

Fig. 3 presents results from tensiometers installed at

80 cm and 140 cm from the face in each instrumented

layer of the model. In general, the initial matric

suctions of soil were similar for all reinforced layers

and increases of matric suction were observed with

time. Higher rates of matric suction increasing

occurred in the lower layers, with values varying from

20 kPa to 80 kPa. In higher layers, matric suction

values ranged from 20 kPa to 30 kPa.

Internal displacements measured by tell-tales with

time are shown in Fig. 4. This figure presents readings

in points located at 0 cm, 30 cm, 60 cm, 90 cm, 120

cm and 150 cm from the wall face. Clearly, higher

rates of displacement increases occurred as soon as

the loading of 100 kPa was applied to the top of the

wall. Thereafter, small increases could be evidenced

with time. In the reinforced layer 2, displacements

were practically constants throughout loading.

Possibly, high values of matric suction of soil

during the wall life avoided reinforcement creep strains,


1256M

atri

c S

ucti

on, u

a-u w

(kP

a)

0

20

40

60

80

100

0 10 20 30 40 50 60 70 80 90 100

Reinforced layer 2

0

20

40

60

80

100Reinforced layer 3

Reinforced layer 4

0

20

40

60

80

1000

20

40

60

80

10080 cm from the face


Reinforced layer 5

Time (days)

80 cm from the face


80 cm from the face


80 cm from the face


Fig. 3 Matric suction measured by tensiometers with time at 80 cm and 140 cm from the wall face.

resulting in a relatively rigid structure. This was

substantiated due to the presence of the concrete

foundation which limits deformation to the reinforced

zone of the structure.

3.2 Strains in the Geotextiles

Reinforcement strains were obtained from the

relative horizontal displacements between facing and

tell-tales attached along the reinforcement length at

different distances. The distribution of relative

displacement along the reinforcement between points

of measurements and wall facing in the reinforced

layer 2 is presented in Fig. 5. In this figure, sigmoidal

curves fitting the raw data are drawn in order to have a

smooth representation of the distribution of

displacements along the reinforcement length.

The sigmoidal fitting shown in Fig. 5 was also used

to evaluate the distribution of strains along the

reinforcement as presented by Zornberg and Arriaga

0.0

0.5

1.0

1.5

2.0

Loading of 100 kPa

Reinforced layer 5

face30 cm from the face

60 cm90 cm

120 cm

150 cm

0.0

0.5

1.0

Loading of 100 kPa face 30 cm from theface

60 cm90 cm120 cm

Reinforced layer 4

0.0

0.5

1.0

1.5

Loading of 100 kPa

Reinforced layer 3face 30 cm from the face

60 cm

90 cm

120 cm

0.0

0.5

1.0

1.5

0 10 20 30 40 50 60 70 80 90 100

Time (days)

Reinforced layer 2 face

30 cm from the face

60 cm 90 cm

120 cm 150 cm

Inte

rnal

dis

plac

emen

t (m

m)

Fig. 4 Internal displacements versus time.

0

0.2

0.4

0.6

0.8

1

1.2

0 300 600 900 1200 1500

Rel

ativ

e d

ispl

acem

ent

(mm

)

Distance from the face (mm)

0 days6 days8 days14 days31 days35 days41 days47 days59 days68 days90 days

Fig. 5 Distribution of relative displacements between tell tales and wall face along the geotextile length.

[12]. Geotextile strains values can be obtained by

calculating relative movements between points of tell

tales at different distance from the reference and

dividing them by the initial distance between rods.

However, the use of this technique may not be

efficient in this case, since the distance between

measured points may not be small enough to get a real

0 300 600 900 1,200 1,500

0 10 20 30 40 50 60 70 80 90 100


1257

strain between points. For this reason, the raw data

from tell tales was initially smoothed by fitting the

data to a sigmoidal curve. Thus, the distribution of

strains along the geotextile length could be obtained

by deriving the displacement function as:

dxcxbea

d /1

(1)

where, d is the tell-tale displacement, x is the distance

from the wall face to the measured point, and a, b and

c are parameters defined by the fitting of sigmoidal

curves to the raw data using the minimum squares

technique. This technique was used in a GSE field

case by Zornberg et al. [13].

The distribution of strains in each instrumented

layer is shown in Fig. 6. The strain levels were very

small with a maximum value of 0.43% in the

reinforced layer 2 and minimum value of 0.15% in the

reinforced layer 4. Additionally, no relaxation or

retraction of reinforcements could be observed.

A consistent distribution of strains was obtained by

the derivation of a sigmoidal fitting curve and a

Rankine failure surface seems to properly fit it,

assuming a friction angle from C-U triaxial tests on

unsaturated samples.

The effect of matric suction on the stiffness of soil

can be a good explanation for very small strains and

displacements even using extensible reinforcements as

nonwoven geotextiles. Additionally, interface shear

behavior is absolutely improved under unsaturated

conditions [5]. Other aspects requiring further

consideration is the tensile and creep behavior of

nonwoven geotextiles under confined conditions [14].

These influences are not discussed as part of this

paper as they are covered in detail elsewhere [1].

3.3 Limit Equilibrium Analysis

Factors of safety were calculated by limit

equilibrium analyses in order to compare design

parameters and measured values. Limit equilibrium

analyses were conducted using the technical software

UTEXAS3 from the University of Texas, by Wright

[15]. This software allows for analysis of slopes and

walls considering the reinforcement contribution and

interpolating negative pore water pressures (matric

suction) in the soil.

The effect of matric suction on the factor of safety

and reinforcement peak strains can be better

understood through examination of Fig. 7, where the

factor of safety and reinforcement peak strains are

plotted as function of the average of matric suction

measured by all the tensiometers installed in the

model. From this plot, the factors of safety increased

linearly with matric suction and a better stability could

be noted with the time.

No significant changes in measured values of peak

strains with matric suction could be evidenced, and

significantly small levels of strains were noticed.

Therefore, small forces were mobilized by

reinforcement, and, possibly, this structure would be

0

0,2

0,4

0 300 600 900 1200 1500


Rankine failure surface

0

0,1

0,20

0,1

0,20

0,1

0,2

0

0 days6 days

8 days14 days31 days35 days41 days47 days59 days

Days after construction:

Geo

text

ile

stra

ins

(%)

Fig. 6 Distribution of strains.

0

0.2

0.4

0.6

0.8

1

1

1.5

2

2.5

3

-10 0 10 20 30 40 50 60 70 80

Peak

str

ains

(%)

Fact

or o

f sa

fety

Average of matric suction (kPa)

Factor of safety x Average of matric suction

Peak strains x Average of matric suction

Saturated condition (suction zero)

Fig. 7 Limit equilibrium analyses: effect of matric suction on factors of safety and reinforcement peak strains.

0.2

0.10

0.20.10

0.20.1

00.40.2

0300 600 900 1,200 1,500


1258

0

30

60

90

120

150

0 300 600 900 1200 1500

H (

cm)


14 dias

41 dias

68 dias

90 dias

14 dias

41 dias

68 dias

90 dias

14 days

41 days

68 days

90 days

14 days

41 days

68 days

90 days

Days after construction:

Predicted

Measured

Fig 8 Slip surfaces from equilibrium limit analyses in different times.

stable even without reinforcements. In this case,

reinforcements perform purely the constructability

function.

Fig. 8 summarizes the slip surfaces obtained from

limit equilibrium analyses inputting matric suction

values. This analysis was conducted in order to

compare failure surface location from measured peak

strains and predicted slip surface.

Rankine failure surface (Fig. 6) showed better

agreement than a circular slip surface from limit

equilibrium analyses, even though factors of safety

using Rankine stress state are much more conservative.

Additionally, no influence of matric suction was

observed on potential slip surface shapes, nor failure

surfaces from measured strains.

4. Conclusions

The following conclusions can be drawn from the

analysis of the data collected as part of this

investigation:

(1) Significantly small internal displacements and

reinforcement strains illustrated the positive effect of

matric suction on the wall’s performance;

(2) Although the matric suction increased with time,

no reinforcement retraction was observed. Still, no

changes on peak strains with time were noted in this

study. Thus, creep strains potentials seem to be

minimized by the soil matric suction, even though

creep occurs over a significantly longer period than

that exploited in this study;

(3) Limit equilibrium analyses have shown the

increase of factor of safety with matric suction. The

relationship between reinforcement peak strains with

increasing factor of safety was horizontally linear,

which means no changes of strains with matric

suction;

(4) Small forces were mobilized by reinforcement,

and, possibly, this structure would be stable even

without reinforcements. In this case, reinforcements

served the function of “internal drainage” which

supports the work by Wayne and Wilcosky [9].

Therefore, the structure have proved to work

significantly well under unsaturated condition due to

the increase of soil stiffness. As a result, small forces

are transmitted to the reinforcements and low strength

material can be adopted. Restriction of wetting front

by means of an internal drainage system and/or water

barriers, and the use of unsaturated poorly draining

soils, can be an economical alternative for retaining

walls or reinforced slopes.

References

[1] V. Elias, B.R. Christopher, Mechanically Stabilized Earth Walls and Reinforced Soil Slopes Design and Construction Guidelines, FHWA (Federal Highway Administration), FHWA-SA-96-071, Washington, DC, 2010, p. 371.

[2] Standard Specifications for Highway Bridges, 17th ed., AASHTO (American Association of State Highway and Transportation Officials), 2002.

[3] C. Yoo, H.Y. Jung. Case history of geosynthetic reinforced segmental retaining wall failure, Journal of Geotechnical and Geoenvironmental Engineering 132 (12) (2006) 1538-1548.

[4] J.S. Fowze, D.T. Bergado, S. Soralump, M. Voottipreux, Rain-triggered landslides hazards and mitigation measures in Thailand: From research to practice, Geotextile and Geomembranes 30 (1) (2012) 50-64.

[5] C.N. Khoury, G.A. Miller, K. Hatami, Unsaturated soil-geotextile interface behavior, Geotextile and

0 300 600 900 1,200 1,500


1259

Geomembranes 29 (2010) 17-28. [6] M. Ehrlich, D. Vidal., P.A. Carvalho, Performance of two

geotextile reinforced soil slopes, in: Proceedings of International Symposium on Recent Developments in Soil and Pavement Mechanics, 1997, pp. 415-420.

[7] F.H.M. Portelinha, B.S. Bueno, J.G. Zornberg, Performance of nonwoven geotextiles reinforced soil walls under wetting conditions: Laboratory and field investigation, Geosynthetics International 20 (2) 90-104.

[8] R.M. Koerner, T.Y. Soong, Geosynthetic reinforced segmental retaining walls, Geotextiles and Geomembranes 19 (6) (2001) 359-386.

[9] M.H. Wayne, E. Wilcosky, An innovative use of a nonwoven geotextile in the repair of Pennsylvania State Route 54, Geotechnical Fabrics Report 14 (7) (1996) 26-29.

[10] D.V. Raisinghani, B.V.S. Viswanadham, Evaluation of permeability characteristics of a geosynthetic-reinforced soil through laboratory tests, Geotextile and Geomembranes 28 (6) (2010) 579-588.

[11] D.V. Raisinghani, B.V.S. Viswanadham, Centrifuge model study on low permeable slope reinforced by hybrid geosynthetics, Geotextile and Geomembranes 28 (6) (2011) 579-588.

[12] J.G. Zornberg, F. Arriaga, Strain distribution within geosynthetic-reinforced slopes, Journal of Geotechnical and Geoenvironmental Engineering 129 (1) (2003) 32-34.

[13] J.G. Zornberg, B.R. Christopher, J.K. Mitchell, Performance of a geotextile reinforced slope using decomposed granite as backfill material, in: Proceedings of Second Brazilan Simposium on Geosynthetics Applications, São Paulo, 1995, pp. 19-29.

[14] A. McGown., K.Z. Andrawes, M.H. Kabir, Load-extension testing of geotextiles confined in-soil, in: Proceedings of International Conference on Geotextiles, USA, 1982, pp. 793-798.

[15] S.G. Wright, UTEXAS3: A Computer Program for Slope Stability Analyses Calculation, Shinoak Software, Austin, Texas, 1990.


Models and Optimization of Rice Husk Ash-Clay Soil

Stabilization

Iloeje Amechi Francis1 and Aniago Venantus2

1. Department of Architecture, Enugu State University of Science and Technology, Enugu 400261, Nigeria

2. Department of Civil Engineering, Enugu State University of Science and Technology, Enugu 400261, Nigeria

Abstract: Soil stabilization has been found to be very effective in upgrading the bearing capacity of weak soils for construction purposes. The stabilizing agent, for cost efficiency, ought to provide a cheaper alternative to other possible processes. With the rapid industrialization efforts around the globe, enormous quantities of waste materials are generated and there has not been adequate mechanism for recycling and re-use of such wastes to reduce the consequent environmental problems and hazardous situations created as a result. The objective of the study is to upgrade expansive soils from Eke Obinagu, Ugwuaji in Enugu State and Egbede in Abia State Nigeria, as constructions material using RHA (rice husk ash). Expansive clay soils were mixed with this ash, remolded and tested to examine the effect on the OMC (optimum moisture content) and the CBR (California Bearing Ratio). The characterization of the soils was done in accordance with BS1377 and 1990b, with respect to their engineering properties which include OMC, MDD, Soaked CBR, Liquid Limit, Classification and Sieve Analysis. The rice husk was burnt and prepared in a cylindrical incinerator to form the ash. The results of classification showed A-7-5, A-6, A-2-7 soils for Eke Obinagu, Egbede and Ugwuaji, respectively. The CBR values showed increase from 5% to 29%, 7% to 13% and 5% to 23% for A-7-5, A-6 and A-2-7 respectively at optimal value of 17.5% stabilization. There was also an appreciable increase in the OMC values from 15% to 33%, 14% to 25% and 15% to 31% for A-7-5, A-6 and A-2-7 soils respectively at 17.5% stabilization. Empirical models based on Scheffe’s model were developed with the experimental results and the equations resulting from the second degree polynomials of Scheffe’s models were solved using the least square method. The models developed showed close correlation with the experimental results for the A-7-5 and A-6 soils and will form good guide in pavement and foundation designs in the study areas.

Key words: Models, stabilization, CBR, RHA, clay.

1. Introduction

Soil as a material is easily the most abundant of all

natural resources but yet very scarce when needed as a

construction material. In developing countries,

demand for this material is on a daily increase. With

increase in road and building construction activities in

the southeastern Nigeria, high demand has been

placed on the soil with the result that those that

qualify for use for construction purposes are almost

out of stock. This creates an urgent need, in Nigeria as

well as other areas round the globe, for increased

effort towards improving any available soil, for use,

within the locality. In road construction, the

Corresponding author: Iloeje Amechi Francis, M.Sc.,

research field: environmental management/architecture. E-mail: [email protected].

underlying principle is to employ high quality sub

grade materials to effect a substantial reduction in the

thickness of pavement, thereby effectively reducing

the overall cost of construction while still maintaining

a long life span for the constructed road.

In the southeastern Nigeria, quality soils used for

sub grade are in very short supply. Others are largely

deficient in their engineering properties making them

very unfit for use in construction and thus requiring

some degree of stabilization to enhance the quality

before use. In Enugu and Abia States, the study areas,

huge quantities of waste materials are produced and

the disposal mechanism does not match the rate of

production, thereby creating environmental problems

and hazardous situations. Adequate and safe disposal

of such materials are very vital and can be addressed

DAVID PUBLISHING

D

Models and Optimization of Rice Husk Ash-Clay Soil Stabilization

1261

by finding ways to improve and utilize them for other

useful purposes. Numerous works have been done on

stabilization of soil using waste products and these

have been able to prove that a substantial percentage

of wastes when combined with other materials can

produce highly beneficial results. One such material

produced in large quantities, in the study areas,

without adequate disposal plan, is the RHA (rice husk

ash). This material can be harnessed and effectively

used in combination with other materials to produce

useful results. It has been classified into high carbon

char, low carbon ash and carbon free ash [1]. Due to

its refractory properties, it is most wanted in steel,

ceramic and brick factories [2].

Several researchers carried out experimental studies

on the use of this material to upgrade the soil

properties. A study on strength characteristics of clay

soil stabilized with lime and the ash was conducted by

Ref. [3]. The unconfined compressive strength and

soaked CBR (California Bearing Ratio) tests for

different combinations of the stabilizing agents

showed that 4% lime is very close to the optimal value

either as sole additive or with any other secondary

additive, from the view point of optimum efficacy. Ali

and Sreenivasulu [4], also carried out an experimental

investigation on the influence of the ash and lime on

the Atterberg’s limits, strength, compaction, swell and

consolidation properties of bentonite. The results

showed that the plasticity properties of bentonite were

significantly modified upon their addition. There was

also a noticeable influence of these materials on

compaction, strength, swell and consolidation

properties of bentonite soil particularly at 15% and

8% stabilization, respectively. Another study carried

out by Chattopadhyay and Roy [5], explored the

possibility of alternative materials like pond ash to be

used wholly or partially for the construction of roads

as well as manufacture of bricks. Mahmud and

Muntohar [6], examined the possibilities of improving

residual soil properties with this ash and cement in

suitable proportions as stabilizing agents. Chandra

et al. [7], used ash from rice mill and lime sludge from

paper factory (all waste products), to demonstrate that

the PI (plasticity index) value of clay soil decreases

from twelve to eight when mixed with 10% ash and

16% lime sludge. Furthermore, with increase in the

proportions of these materials, the dry density of the

soil decreases whereas the OMC (optimum moisture

content) increases. The UCS (unconfined compressive

strength) was observed to have optimal value

corresponding to 10% ash and 16% lime sludge. The

soaked CBR value increases with increase in these

materials. The optimal values of the proportions of

these two materials for maximum UCS and lowest PI

were estimated to be about 10% and 16%, respectively.

These results showed that these materials are excellent

additives, in optimal proportions, for the stabilization

of clayey soil. The stabilized soils can then be

successfully employed for use as sub grade or

sub-base for roads or pavement construction. While

saving in construction costs, the environment is also

rid of enormous deposits of waste.

Soil stabilization generally has been found to be

useful in upgrading the bearing capacity of weak soils

for building purposes. This has increased the potential

benefits of using some waste products, against cement,

as stabilizing agents. The major challenge now is to

develop mathematical models that will encourage

wider and easier application of soil improvement

techniques.

This study will examine the use of the ash to

upgrade an expansive clay soil, for use as a

construction material. The percentage of this material

that will generate better result in the engineering

properties of the soil will also be examined with a

view to formulating a model for RHA-Clay soil

stabilization.

2. Materials and Methods

2.1 Study Areas

The soil samples were collected from three different

locations of Enugu and Abia states, in the


1262

southeastern Nigeria. These locations are Borrow Pit

sites for most of the road contracting firms in the

states and they include: Eke-Obinagu Borrow Pit,

Nike, Enugu state; Egbede Borrow Pit, Aba, Abia

state and Ugwuaji Borrow Pit, Nkanu, Enugu state.

2.2 Characterization of Clays

Clays are rarely formed separately. They are mixed

with other materials such as microscopic crystals of

carbonates, feldspars, micas and quarts. Clay minerals

are divided into four major groups: kaolinite,

montmorillonite/smectite, illite and chlorite groups.

The compositions of clay minerals depend on

geographic area and the bedrock, and vary a lot all

over the world. Clay soils have high plasticity index.

According to Arora (2006), LL (liquid limit) is the

water content at which the soil changes from liquid

state to plastic state, while the PL (plastic limit), is the

water content at which the soil changes from plastic

state to semi-solid state. PI (plasticity index) is the

numerical difference between the liquid limit and the

plastic limit expressed as: PI = (LL – PL). Soils with

high PI indicate the presence of high proportion of

clay fraction, while soils with lower PI tend to be silt.

2.3 Characterization of RH (Rice Husk) and RHA

(Rice Husk Ash)

RH (rice husk) is a by-product of the rice mill

industry [8-10]. By weight, 10% of the rice grain is

rice husk [11]. Jha and Gill [10] in their experimental

study observed that for every 4 tons of rice, 1 ton is

the rice husk. Similar study carried out by Alhassan

[9], revealed that about 108 tons of rice hush is

generated annually in the world. In Nigeria, about 2

million tons of rice are produced annually, while in

Niger state alone, about 96,600 tons of rice grains are

produced annually [12]. The husk generated from

these will be enormous and is usually disposed

carelessly by dumping in an open heap near the mill

site or along the roadside where they are burnt.

An analysis of RH as given by Muthadhi et al. [13],

is shown in Table 1.

The ash is obtained from burning the rice husk.

When the husk is burnt, about 15%-20% turns into the

ash. The ash, being so light, is carried away by wind

and water in its dry state. It is difficult to coagulate

and thus contributes to air and water pollution. The

cumulative generation of the ash from rice requires a

large space for disposal and so its utilization and the

exploitation of its inherent properties provide a perfect

way to mitigate the associated environmental

problems. Researchers have found that this ash has

high percentage of siliceous materials and so has

potential pozzolanic properties [14]. According to

Houstin [1], it has been classified into high carbon

char, low carbon ash and carbon free ash. The

properties depend on whether it has undergone

complete destructive combustion or is partially burnt.

Meanwhile, it has been categorized under pozzolana

with about 67%-70% silica, 4.9% aluminum and

0.95% iron oxides [12].

2.4 Sample Preparation and Experimental Program

Soils from Eke Obinagu Borrow Pit, Emene, Enugu

State, Egbede Borrow Pit, Aba, Abia State and

Ugwuaji, Nkanu, Enugu State were used for this study,

while the Rice Husk was sourced from Abakaliki in

Ebonyi State, barely 75 km from Enugu. Only the

CBR and OMC, were considered. The second degree

polynomial was used to model their behavior and the

effects on the soil properties.

On collection of the soil samples, they were first

classified as given in Table 2, using BS 1377 standard

Table 1 Typical analysis of rice husk [13].

Properties Range

Bulk density (kg/m3) 96-160

Length of husks (mm) 2-5

Hardness (Mohr’s Scale) 5-6

Ash (%) 22-29

Carbon (%) 35

Hydrogen (%) 4-5

Oxygen (%) 31-37

Nitrogen (%) 0.23-0.32

Sulphur 0.04-0.08

Moisture 8-9


1263

Table 2 Soil sample classification before stabilization.

No. Properties BS 1377 Classification

1 Eke Obinagu A-7-5

2 Egbede A-6

3 Ugwuaji A-2-7

Source: Field work.

classification method.

After classification the engineering properties of the

soil were determined in accordance with BS1377 and

1990b, and presented in Table 3, while the chemical

properties of the rice husk ash were presented in

Table 4.

The LL (liquid limits) of Eke Obinagu, Egbede and

Ugwuaji were 61%, 40% and 49% before stabilization

while their PI (plasticity index) were 35%, 17% and

18%, respectively. These results indicate that Eke

Obinagu soil with high PI can expand and shrink in

response to wet and dry seasons of the year more than

the rest of the soils. Other properties are as shown in

Table 3. The burning and preparation of the ash was

carried out in a cylindrical incinerator. The CBR test

was carried out on the materials after stabilization.

The moisture content of the soil generally represents

the design conditions for which the test results were

derived and this was also examined.

3. Results, Discussions and Modeling

Before stabilization the CBR value of Eke Obinagu

(A-7-5) sample was 5% and thereafter rose to 29% at

optimal stabilization of 17.5%. For Egbede (A-6)

sample the CBR value was 7% before and 13% after,

while it was 5% and 23% before and after respectively

for Ugwuaji soil at 17.5% stabilization.

The CBR plot in Fig. 1 showed that not all the three

samples met the sub-grade requirement. According to

Nigerian Roads and Bridges specification [15], the

CBR value of sub-grade should be up to 15% or more

after soaking for 48 h. Since the aim of this study is to

know the soils that can respond favorably to

stabilization with the ash, it was discovered that Eke

Obinagu soil (A-7-5) with a CBR value of 29% responds

Table 3 Engineering properties of the soil.

S/No Properties Location

Eke Obinagu

Egbede Ugwuaji

1 OMC (%) 15 14 15

2 MDD (gkm3) 1.72 1.97 1.88

3 Soaked CBR (%) 5.00 6.00 5.00

4 Liquid limit (%) 61 40 49

5 Plasticity index (%) 35 17 18

6 % passing B.S. Sieve size 63 mm

65 39 57

7 Soil classification A-7-5 A-6 A-2-7

Source: Field work.

Table 4 Chemical properties of the RHA.

Compound composition

Rice husk ash at 400 oC (%)

RHA obtained from open air (%)

SiO2 86.56 89.15

CaO 2.97 2.10

MgO 2.14 1.32

Fe2O3 0.63 0.18

Al2O3 3.65 4.32

Na2O 2.701 1.48

K2O 1.251 1.399

Source: Field work.

better than the other two soils. However in all the soil

samples the addition of ash resulted in increase in the

CBR values.

The models shall be obtained based on Sheffe’s

model given as:

E (y)=βo+∑i = 1

p

βi xi2+∑∑

i< j

p

βij xi x j+......+Є (1)

which is the equation of independent variables for 2nd

degree polynomial, where p is the number of

components in the mixture. It is worthy of note that

interests among researchers have changed from

determining which process variables affect the

response, to determining the region or important

factors that lead to the best possible response [16].

Response surface methodology RSM is a collection of

mathematical and statistical techniques useful for the

analysis and modeling of problems in which a

response of interest is influenced by several variables

and the objective is to optimize this response [16-18].

RSM methods lead to product OPTIMIZATION


1264

which is the main object of Scheffe's model. If the

RHA variable is assumed to be x1, while the soil

variable is x2, the number of components in the

mixture is, p = 2. The constraint of Scheffe’s Model

for a mixture design is that

x1 + x2 + …. xp = 1 x1 + x2 = 1 (2)

E(y) =Ff = (β0 + β1 + β11) x1 + (β0 + β2 + β22) x2 + (β12 –

β11 – β22) x1 x2 = μ1 x1 + μ2 x2 + μ2 x1 x2 (3)

Put in a compact form,

F f = ∑1<i < p

p

μi xi+∑ ∑1<i < j <q

p

μij xi x j (4)

The result of the least square method is a system of

linear equations with three unknown constants μ1, μ2,

μ12, which will be determined for each of the soils

obtained from the three locations. From Table 5 the

least square is as shown in Table 6 and the

homogenous equations for the model coefficients are

as follows using Eke Obinagu soil sample:

Table 6 is generated for all the locations:

Eke Obinagu CBR = 14.6469x1 + 0.05x2 – 0.1487x1 x2 (5)

Egbede CBR = 1.7559x1 + 0.0575x2 + 0.0257x1 x2 (6)

Ugwuaji CBR = 7.6021x1 + 0.0464x2 – 0.0743x1 x2 (7)

The above models can be verified using the

optimum results of the stabilized soils given in

Table 7.

The results of both the experiments and the model

values are compared as shown in Tables 8-10 and in

Figs. 1-3.

In all the soil types the addition of the stabilizing

agent resulted in increase in CBR values, collaborated

with the results of the models. The CBR curve for the

model is linear while that of the experiment increased

Table 5 Results after stabilization (OMC, MDD, CBR).

SN RHA (%) Ugwuaji Nkanu A-2-7 Egbede Borrow PIT A-6 Eke-Obinagu A-7-5

OMC (%) MDD (g/cm3) CBR (%) OMC (%) MDD (g/cm3) CBR (%) OMC (%) MDD (g/cm3) CBR (%)

1 0.00 15.00 1.88 5.0 14.00 1.97 6.00 15.00 1.72 5.00

2 2.5 15.00 1.86 5.0 14.00 1.94 7.00 16.00 1.69 6.00

3 5.00 17.00 1.82 7.0 14.00 1.90 9.00 18.00 1.63 7.00

4 7.5 18.00 1.78 9.00 15.00 1.80 10.00 23.00 1.60 8.00

5 10.00 20.00 1.68 15.0 15.00 1.62 11.00 26.00 1.48 22.00

6 12.50 23.00 1.58 17.00 22.00 1.50 11.0 27.00 1.44 23.00

7 15.00 29.00 1.49 22.00 23.00 1.44 13.00 28.00 1.41 28.00

8 17.50 31.00 1.44 23.00 25.00 1.33 12.00 33.00 1.37 29.00

9 20.00 30.00 1.40 18.00 27.00 1.28 9.00 33.00 1.34 26.00

Table 6 Controllable variables for optimum moisture content.

S/NO X1 X2 X1 X2 X12 X2

2 X12 X2 X1 X2

2 X12 X2

2

1 0.00 100.00 0.00 0.00 10,000.00 0.00 0.00 0.00

2 2.50 97.50 243.75 6.25 9,506.25 609.38 23,765.63 59,414.06

3 5.00 95.00 475.00 25.00 9,025.00 2,375.00 45,125.00 225,625.00

4 7.50 92.50 693.75 56.25 8,556.25 5,203.13 64,171.88 481,289.06

5 10.00 90.00 900.00 100.00 8,100.00 9,000.00 81,000.00 810,000.00

6 12.50 87.50 1,093.75 156.25 7,656.25 13,671.88 95,703.13 1,196,289.06

Σ 37.50 562.50 3,406.25 343.75 52,843.75 30,859.38 309,765.63 2,772,617.19

Table 7 CBR/OMC values (for 15%, 17% and 20% stabilization).

S/No RHA (%) Eke Obinagu A-7-5 Egbede A-6 Ugwuaji A-2-7

OMC (%) CBR (%) OMC (%) CBR (%) OMC (%) CBR (%)

1 15.00 28.0 28.0 23.0 13.0 29.0 22.0

2 17.50 33.0 29.0 25.0 12.0 31.0 23.0

3 20.00 33.0 26.0 27.0 9.00 30.0 18.0


1265

Table 8 CBR values for the model and experimental results (Eke Obinagu).

S/No RHA (%) Soil sample (%) CBR experiment (%) CBR Model (%)

1 15.0 85.0 28 23.24

2 17.50 82.50 29.0 29.59

3 20.0 80.0 26.0 36.89

Table 9 CBR values for the model and experimental results (Egbede Sub-base).

S/No RHA (%) Soil sample % CBR experiment (%) CBR model (%)

1 15.0 85.0 13.0 11.3

2 17.50 82.50 12.0 11.12

3 20.0 80.0 9.0 10.6

Table 10 CBR values for the model and experimental results (Ugwuaji Sub-base).

S/No RHA (%) Soil sample (%) CBR experiment (%) CBR model (%)

1 15.0 85.0 22.0 34.36

2 17.5 82.5 23.0 45.76

3 20.0 80.0 18.0 59.02

15 17.5 20

CB

R

RHA (%)

40

35

30

25

20

15

10

5

0

A-7-5

A-7-5

A-6A-6

A-2-7

A-2-7

Fig. 1 Combined plot of CBR against RHA.

1.6

1.4

1.2

1

0.8

0.6

0.4

0.2

0 15 17.5 20

MD

D

RHA (%)

A-2-7

A-2-7

A-7-5

A-7-5

A-6

A-6

Fig. 2 Combined plot of MDD against RHA.

40

35

30

25

20

15

10

5

0 15 17.5 20

OM

C %

RHA (%)

A-2-7

A-2-7A-7-5

A-7-5

A-6

A-6

Fig. 3 Combined plot of OMC against RHA.

slightly and decreases linearly at 17.5% stabilization

for the Ugwuaji. Decrease in CBR value when the

agent is increased suggests that the lack of cementing

properties is a disadvantage to its use as a stabilizer

for expansive soils. For this reason, it should be used

with lime-containing material or cement for soil

improvement.

4. Conclusions

The results of the models closely correspond with

the experimental results especially with A-7-5 and

A-6 soils and so the models could be used to predict

the Siol—RHA properties in the absence of

ExperimentModel

ExperimentModel

ExperimentModel


1266

experimental results. In all the soil types, the addition

of the stabilizing agent resulted in increase in OMC

and CBR values similar to results from other

literatures on the subject. At 15% to 17.5%

stabilization the soils attained their maximum CBR

values although the A-6 soil had the lowest values.

These behavioral changes were also observed in the

results of the models but the pattern of improvement

varies with the different soils. This study therefore

recommends that thus: Although ash from rice is a

good stabilizing agent for expansive soils it will

require lime-containing material or cement to achieve

better results, the empirical models developed could

be used to predict the properties of the stabilized soil

in the absence of experimental data for the A-7-5 and

A-6 soils.

References

[1] D.F. Houstin, Rice Chemistry and Technology, American Association of Cereal Chemistry, Inc., St. Paul, Minnesota, 1972, pp. 301-340.

[2] C.S. Prasas, K.N. Maiti, R. Venugopal, Effect of RHA in white wave composition, Ceramics International 27 (2000) 629.

[3] G.V.R.P. Raju, B.P.C. Sekhar, B.R.P. Kumar, G. Mariyana, Strength characteristics of expansive soils stabilized with lime and rice husk ash, in: Proceedings of the National Seminar on Road Transportation: Issues and Strategies, Patiala, 1998, p. 20.

[4] M. Ali, V. Sreenivasulu, An experimental study on the

influence of rice husk ash and lime on properties of

bentonite, in: Proceedings of the Indian Geotechnical

Conference, India, 2004, p. 468.

[5] B.C. Chattopadhyay, T.K. Roy, Uses of soil as road

material with different technologies for improvisation, in:

Proceedings of the National Conference on Advances in

Road Transportation (ART), NIT Rourkela, 2005, p. 491.

[6] E.A. Basha, R. Hahim, H.B. Mahmud, A.S. Muntohar,

Stabilization of residual soil with RHA and cement,

Journal of Construction and Building Materials 19 (6)

(2005) 448-553.

[7] S. Chandra, S. Kumar, R.K. Anand, Soil stabilization

with rice husk ash and lime sludge, Journal of Indian

Highways 33 (5) (2005) 87-98.

[8] J.K. Mitchell, Practical problems from surprising soil

behavior, J. Geotechnical Engineering 112 (3) (1996)

255-289.

[9] M. Alhassan, Potential of rice husk ash for soil stabilization,

AU Journal of Technology 11 (4) (2008) 246-250.

[10] J.N. Jha, K.S. Gill, Effect of rice husk ash on lime

stabilization, Journal of the Institute of Engineering India,

87 (2006) 33-39.

[11] P.K. Mehta, Concrete Structure, Properties and Materials,

Prentice-Hall Eagle-Wood Cliffs, New Jersey, 1986, pp.

256-289.

[12] E.B. Oyetola, M. Abdullahi, The use of rice husk ash in

low-cost sandcrete block production, Leonardo Electronic

Journal 8 (2006) 58-70.

[13] A.C. Muthadhi, R. Anitha, S. Kothandaraman, Rice husk

ash—Properties and its uses, A Review IE (I) Journal 88

(2007) 50-56.

[14] D.J. Cook, R.P. Pama, S.A. Damer, Rice husk ash as a

pozzolanic material, in: Proceeding of Conference on

New Horizons in Construction Materials, Lehigh

University, Lehigh, 1976.

[15] Specification Limits for Materials for Roads and Bridges,

Federal Ministry of Works, Nigeria, 1997.

[16] D.C. Montgomery, Designs and Analysis of Experiments,

6th ed., John Wiley and Sons, New York, 2005.

[17] R.H. Myers, D.C. Montgomery, G.C. Vining, C.M.

Borror, S.M. Kowalski, Response surface methodology:

A retrospective and literature survey, Journal of Quality

Technology 36 (2004) 53-77.

[18] R.H. Myers, D.C. Montgomery, A tutorial on generalized

linear models, Journal of Quality Technology 29 (1997)

274-291.


Gully Erosion Study and Control: A Case Study of Queen

Ede Gully in Benin City

Jacob O. Ehiorobo and Roland O. Ogirigbo

Department of Civil Engineering, Faculty of Engineering, University of Benin, Benin 300283, Nigeria

Abstract: This paper presents findings from studies carried out on the Queen Ede gully erosion site in Benin City, in the south-southern zone of Nigeria. The studies involved detailed topographical, geotechnical, meteorological and hydrological data acquisition. The data were processed and analyzed to determine catchment size, gully morphology, soil characteristics, rainfall pattern and hydrological pattern. These were then interpreted and used to determine the method of control to be adopted. The adopted control measures is a combination of structural and non-structural methods. The structural method involved the use of gully control structures to divert the runoff entering the gully from the head, while the non-structural method involved the use of boulders and vegetation to stabilize the gully walls around the head region. Key words: Queen Ede gully, gully erosion, catchment, control structures.

1. Introduction

Gully erosion is an enormous type of environmental

degradation which results in loss of valuable land used

for agricultural, domestic, industrial and aesthetic

purposes, as well as loss of property and even human

lives [1]. It is formed as a result of water moving in rills,

which concentrate to form larger channels. When rill

erosion can no longer be repaired by merely tilling or

disking, it is defined as gully erosion.

Generally, gully erosion occurs when runoff

concentrates and flows at a velocity sufficient to detach

and transport soil particles. In Nigeria, high land use

pressure particularly in the south-east and south-south

regions render the landscape more vulnerable to gully

erosion. Land use changes have also caused the

development of bank gullies along some river banks [2].

A recent study conducted in the south-eastern parts of

Nigeria, showed that the primary causes of gully

erosion in this region is as a result of roads lacking

Corresponding author: Jacob O. Ehiorobo, Ph.D., research

fields: GNSS and geodetic positioning, deformation surveys and analysis, engineering and construction surveys and analysis, engineering and construction surveys, remote sensing, GIS, water resources modeling and environmental hazards analysis. E-mail: [email protected].

proper drainage, unguided cultivations, and

indiscriminate channelling of flood water on sloped

terrain [3]. Also, changes in drainage pattern associated

with urbanization can give rise to the formation of

gullies especially where illegal settlements exist.

Gully erosion is the most destructive form of erosion

as it destroys the soil structure, damage farm lands,

destroy infrastructure, alter transportation corridors

and lower water tables [4]. According to Ref. [5], the

formation of gullies in the south-eastern part of Nigeria

has become one of the greatest environmental disasters

facing many towns and villages, as many agricultural

lands have become unsuitable for cultivation and

hundreds of people have had to relocate. Efforts are

however being made to control some of these gullies as

reported in Ref. [6].

A study conducted by Poesen [7] stated that soil

shear strength at saturation of various soil horizons is a

good indicator of their resistance against concentrated

flow erosion. In Ezezika and Adetona [3], it was

concluded that most of the gullies in the south-eastern

part of Nigeria can be prevented from expanding by

embarking on enhanced public awareness programs

and better land management practices. While these

DAVID PUBLISHING

D

Gully Erosion Study and Control: A Case Study of Queen Ede Gully in Benin City

1268

practices can prevent the formation of future gullies,

they are insufficient to control the huge gully erosion

sites already existing.

Apart from the south-eastern parts of Nigeria, gully

erosion still plagues other areas like the south-southern

regions where Edo state is located. In order to

adequately address the problems associated with gully

erosion in this region, proper studies would have to be

carried out to determine the topographical, geological,

geotechnical, meteorological and hydrological

characteristics of gullies in the region. On the gullies in

this region, very little research have been done on the

state of the gullies, the processes involved and control

measures (both temporary and long-term) that can be

put in place to ensure that the growth of the gullies are

investigated.

It is to be noted that despite several case studies

reported in literature, there is still the need for more

research on the effectiveness and cost-efficiency of

gully prevention and control measures. This is because,

the effectiveness of many of these control measures

depends on local conditions. For instance, it was

reported that stabilizing a bank gully head in central

Belgium with rock plug did not work in loess-derived

soils and an alternative technique with geo-membranes

had to be developed [8, 9].

This paper presents the findings from studies carried

out on the Queen Ede gully erosion site in Benin City

(south-south zone of Nigeria), and the solution

adopted to prevent further growth and expansion of the

gully by applying both structural and non-structural

measures.

2. Methodology

2.1 The Study Area

The Queen Ede gully erosion site is located in Benin

City, the capital city of Edo state in Nigeria. It lies

within the UTM (Universal Traverse Mercator) zone

31 and is bounded by UTM coordinates 700,800 mN to

702,500 mN and 795,800 mE to 796,000 mE. The

gully runs down to the Ikpoba River in a south eastern

direction, covering a total land area of 59,250.099 m2,

with a perimeter of 2,219 m.

The study area lies within the tropical rain forest

zone and is characterized by annual rainfall ranging

from 1,558.1 mm in 2001 to 2,618.3 mm in 2010. The

elevation of the study area ranges from 16 m to 110 m

above mean sea level. The location plan of the queen

Ede gully erosion site in Benin City is shown in Fig. 1.

2.2 Causes of Gully Erosion Problem and Previous

Efforts at Rehabilitation

The Queen Ede gully is believed to have started

sometime in the 1990s, as a result of the abrupt

termination of the outlet drain from the Benin-Agbor

highway around the current location of the gully.

Additionally, the runoff for the steep slope from streets

within the upland catchment area contributed largely to

the formation of the gully. For instance, there are four

900 mm diameter culverts under the Benin-Agbor

highway, which carry the storm discharge from the

neighbouring streets located around the gully head to

two catch pits located on the opposite side of the

highway. An assessment of the catch pits indicated that

they are inadequate in size compared to the volume of

storm runoff they receive at a time and therefore they

can not serve the purpose for which they were

constructed.

Efforts have been made in recent years by both the

State and Federal Government to arrest the acceleration

of the erosive action of the storm water in the area but

these have not succeeded. Even recently, the local

residents constructed a local earth channel to divert the

storm runoff coming towards the gully from the streets

within the upland catchment area, but this resulted in

creating a secondary gully at the gully head.

2.3 Field Survey Measurements

Field reconnaissance survey was carried out using

handheld Garmin 76 GPS, to capture key coordinates.

Three control points were established at some distance

on stable ground from the gully head by method of


1269

Fig. 1 Location of Queen Ede gully erosion site in Benin City.

Differential GPS. Leica Total Station instrument was

then used for detailed surveys within the catchment

basin to capture both the primary gully at Queen Ede

and the other secondary gullies along Edebor and

Pohgah streets.

Measurements were carried out to obtain the cross

section of the gully and the topographical profile along

the axis of the main gully channel from the head to the

terminal point at Ikpoba River.

Total station measurements were collected at 1 cm


1270

level resolution to capture break in slopes and other

topographic features necessary for producing DEM

(digital elevation models) and to determine various

morphological parameters such as width, depth,

volume of soil loss, etc..

High resolution Ikono Imagery was acquired for the

study area in order to measure and monitor the extent

of the land area at risk, land use pattern, delineation of

the catchment basin and analysis of infrastructure at

risk or endangered by the gully. The topographical map

of the Queen Ede gully erosion site is shown in Fig. 2.

TIN (Triangulated Irregular Network) model of the

gully site is shown in Fig. 3a while SPOT satellite

image map of the site is shown in Fig. 3b.

Fig. 2 Topographical map of Queen Ede gully and its catchment basin.


1271

(a)


1272

(b)

Fig. 3 The gully: (a) TIN (triangulated irregular network) model of the gully; (b) Ikono imagery of gully.

2.4 Geotechnical Investigation

Soil samples were collected from gully cross section

along the bed and walls at specific locations and taken

to the laboratory for testing and analysis. The tests

carried out included natural moisture content,

Atterberg limit tests, specific gravity tests, gradation,

California Bearing Ratio tests, compaction tests, U-U

triaxial and direct shear tests.

2.5 Hydrological Studies

Nigeria receives rainfall from the south westerlies

which invade the country from the Gulf of Guinea

Coast. The moist air stream is overlain by the north

east trade wind which originates from the Sahara,

which is dry and dusty. The zone where these two air

masses meet is a zone of moisture discontinuity and it

is referred to as the ITD (inter tropical discontinuity).

The rainfall producing system for Nigeria is a

function of the migration pattern of the ITD.

Meteorological data have shown that the rainfall

pattern in Nigeria have changed in the past decades,

due to climate changes caused primarily by the effects

of global warming. For example, the rainy season for

the year 2012 began in late January, as against the usual

periods of March and April. The monthly rainfall


1273

distribution for 2001-2010 was obtained from Benin

meteorological station.

Using a design period of 2, 5, 10, 25, 50 and 100

years duration, respectively, IDF (intensity duration

frequency) curves were prepared for the study area.

Once the catchment basin has been delineated,

rainfall intensity for the study area was computed using

rainfall duration, equal to the time of concentration

(TC), where, . .

. , in minute [1].

3. Data Processing and Results

Spot elevation along with points coordinates were

obtained from the Total Station instrument using the

in-built software of the instrument.

Based on the points coordinates, morphological

cross sections were obtained at 20 m interval. Other

morphological parameters were calculated including

length, width, depth and areas. The morphological

parameters are shown in Tables 1 and 2.

Using arc GIS 9.2 software, DEMs (digital elevation

models) along with contours were plotted. This was

then superimposed on the Ikono Imagery for catchment

basin delineation and analysis.

Also cross sections were plotted at 20 m interval and

bed profile from the head to the point of discharge.

These are shown in Fig. 4, Figs. 5a and 5b,

respectively.

The results of the soil tests from samples taken from

both the gully bed and gully walls revealed that:

• The soil’s specific gravity ranged from 2.37-2.66;

• More than 37.69% of the samples passed through

Sieve No. 0.075 mm;

• Liquid limit ranged from 27.71%-3.55%,

plasticity limit (10.39%-27.04%), plasticity index

(13.11%-49.8%);

• Maximum dry density ranged from 1.19-1.87

g/cm2;

• Angle of internal friction, Ø = 15o and cohesion, C

= 2 kN/m2;

• CBR (California bearing ratio) values were very

low (less than 5%) for both soaked and unsoaked.

The monthly rainfall for 2001-2010 is presented in

Table 3 and Fig. 6. Using Eq. (1), the time of

concentration was computed to be equal to 34 min.

This is the time required to move surface runoff

from the remotest point of the catchment basin to its

outlet.

Rainfall Intensity Duration Curve was used

estimate the effect of rain drop on gully wall and gully

head erosion at the site (Table 3 and Fig. 6)

4. Analysis and Discussion

From Tables 1 and 2, the maximum width of the

gully as in January 2012 was 112 m and the minimum

width was 15.6 m. The maximum depth was 16.4 m

and the minimum depth was 0.4 m. The WDR (width

to depth ratio) varied from 2 to 42. The volume of soil

Table 1 Morphological parameters of Queen Ede Gully as at January 2012.

Chainage (m) Top width, B (m) Depth, D (m) BDR Cross sectional area, A (m2) Cumulative volume, V (m3)

00 + 000 15.604 0.374 42 3,510 0.000

00 + 100 101.218 9.155 11 431,335 25,544.340

00 + 200 74.184 12.394 6 709,756 77,353.480

00 + 300 31.752 8.432 4 213,881 118,422.800

00 + 400 56.205 8.981 6 381,768 144,309.500

00 + 500 70.000 16.378 4 841,278 227,958.000

00 + 600 112.000 13.409 8 970,039 314,372.000

00 + 700 17.363 9.854 2 128,751 344,273.800

00 + 800 19.365 7.780 2.5 127,897 354,944.560

00 + 900 77.226 3.890 20 196,260 368,975.840

00 + 960 40.815 4.480 9 85,271 393,069.580

Tabl

e 2

Mor

phol

ogic

al p

aram

eter

s of Q

ueen

Ede

for

2010

-201

1.

Ch

Top

wid

th

B

otto

m w

idth

Dep

th

C

ross

-sec

tion

area

Vol

ume

C

um v

olum

e of

soi

l los

s 20

10

2011

D

IFF

201

0 20

11

DIF

F 2

010

2011

D

IFF

201

0 20

11

DIF

F 2

010

2011

D

IFF

201

0 20

11

DIF

F 00

+00

15.6

04

15.6

0 0.

000

10.

000

10.0

00

0.00

0

0.37

4 0.

374

0.00

0

3.51

0 3.

510

0.00

0

0.00

0 0.

000

0.00

0

0.00

0 0.

000

0.00

0 00

+20

36.9

93

36.9

9 0.

000

13.

466

13.4

66

0.00

0

3.47

8 3.

478

0.00

0

55.1

72

55.1

72

0.00

0

1,10

3.44

0 1,

103.

440

0.00

0

1,10

3.44

0 1,

103.

440

0.00

0 00

+40

62.7

02

68.5

8 5.

878

28.

556

28.9

20

0.36

4

4.75

1 4.

751

0.00

0 1

73.4

67

176.

780

3.31

3

3,46

9.34

0 3,

535.

600

66.2

60

4,57

2.78

0 4,

639.

040

66.2

60

00+6

0 39

.300

43

.29

3.99

0 2

9.87

3 30

.002

0.

129

9.

889

9.88

9 0.

000

242

.322

24

7.67

0 5.

348

4,

846.

440

4,95

3.48

0 10

7.04

0

9,41

9.22

0 9,

592.

520

173.

300

00+8

0 61

.687

61

.69

0.00

3 1

7.50

0 17

.500

0.

000

7.

846

7.84

6 0.

000

316

.256

31

6.25

6 0.

000

6,

325.

120

6,32

5.12

0 0.

000

15

,744

.340

15

,917

.640

17

3.30

0 00

+100

99

.454

10

1.20

1.

746

81.

556

82.8

77

1.32

1

9.15

5 9.

155

0.00

0 4

29.7

39

431.

335

1.59

6

8,59

4.78

0 8,

626.

700

31.9

20

24,3

39.1

20

24,5

44.3

40

205.

220

00+1

20

76.5

54

76.5

5 0.

000

65.

996

65.9

96

0.00

0

6.98

8 6.

988

0.00

0 3

28.3

21

328.

321

0.00

0

6,56

6.42

0 6,

566.

420

0.00

0

30,9

05.5

40

31,1

10.7

60

205.

220

00+1

40

80.2

97

80.3

0 0.

003

66.

556

66.5

56

0.00

0 1

3.78

8 13

.788

0.

000

726

.142

72

6.14

2 0.

000

14,

522.

840

14,5

22.8

40

0.00

0

45,4

28.3

80

45,6

33.6

00

205.

220

00+1

60

81.6

27

81.6

3 0.

000

69.

246

69.2

46

0.00

0 1

0.58

5 10

.585

0.

000

593

.031

59

3.03

1 0.

000

11,

860.

620

11,8

60.6

20

0.00

0

57,2

89.0

00

57,4

94.2

20

205.

220

00+1

80

76.5

33

76.5

3 0.

000

71.

784

71.7

84

0.00

0

7.11

2 7.

112

0.00

0 2

83.2

07

283.

207

0.00

0

5,66

4.14

0 5,

664.

140

0.00

0

62,9

53.1

40

63,1

58.3

60

205.

220

00+2

00

74.1

84

74.1

8 0.

000

60.

000

60.0

00

0.00

0 1

2.39

4 12

.394

0.

000

709

.756

70

9.75

6 0.

000

14,

195.

120

14,1

95.1

20

0.00

0

77,1

48.2

60

77,3

53.4

80

205.

220

00+2

20

75.8

20

82.1

6 6.

340

60.

870

60.0

00

-0.8

70

13.0

07

13.0

07

0.00

0 8

97.0

77

914.

951

17.8

74

17,9

41.5

40

18,2

99.0

20

357.

480

95

,089

.800

95

,652

.500

56

2.70

0 00

+240

40

.418

50

.17

9.75

2 3

2.23

2 32

.232

0.

000

10.

727

10.7

27

0.00

0 3

57.1

97

386.

809

29.6

12

7,14

3.94

0 7,

736.

180

592.

240

102

,233

.740

10

3,38

8.68

0 1,

154.

940

00+2

60

41.9

71

54.2

7 12

.299

37

.500

38

.060

0.

560

7.

492

7.49

2 0.

000

288

.332

31

3.48

1 25

.149

5,

766.

640

6,26

9.62

0 50

2.98

0 1

08,0

00.3

80

109,

653.

300

1,65

7.92

0 00

+280

36

.292

49

.53

13.2

38

22.5

00

22.5

00

0.00

0

7.20

8 7.

208

0.00

0 2

04.2

10

224.

344

20.1

34

4,04

8.20

0 4,

486.

880

402.

680

112

,084

.580

11

4,14

5.18

0 2,

060.

600

00+3

00

31.7

52

31.7

5 0.

000

18.

026

18.0

26

0.00

0

8.43

2 8.

432

0.00

0 2

13.8

81

213.

881

0.00

0

4,27

7.62

0 4,

277.

620

0.00

0 1

16,3

62.6

00

118,

422.

800

2,06

0.20

0 00

+320

32

.290

32

.29

0.00

0 2

2.09

8 22

.098

0.

000

8.

855

8.85

5 0.

000

220

.372

22

0.37

2 0.

000

4,

407.

440

4,40

7.44

0 0.

000

120

,769

.600

12

2,83

0.24

0 2,

060.

640

00+3

40

30.0

00

30.0

0 0.

000

23.

894

23.8

94

0.00

0

7.97

5 7.

975

0.00

0 2

18.8

55

218.

855

0.00

0

4,37

7.10

0 4,

377.

100

0.00

0 1

25,1

46.7

40

127,

207.

340

2,06

0.60

0 00

+360

31

.780

31

.78

0.00

0 1

9.50

5 19

.505

0.

000

7.

046

7.04

6 0.

000

179

.625

17

9.62

5 0.

000

3,

592.

500

3,59

2.50

0 0.

000

128

,739

.240

13

0,79

9.84

0 2,

060.

600

00+3

80

41.2

97

41.3

0 0.

000

30.

705

30.7

05

0.00

0

8.73

7 8.

737

0.00

0 2

83.7

15

283.

715

0.00

0

5,67

4.30

0 5,

674.

300

0.00

0 1

34,4

13.5

40

136,

474.

140

2,06

0.60

0 00

+400

56

.205

56

.21

0.00

0 4

0.84

1 40

.841

0.

000

8.

981

8.98

1 0.

000

391

.768

39

1.76

8

0.00

0

7,83

5.36

0 7,

835.

360

0.00

0 1

42,2

48.9

00

144,

309.

500

2,06

0.60

0 00

+420

62

.090

62

.09

0.00

0 4

6.44

1 46

.441

0.

000

10.

306

10.3

06

0.00

0 4

99.8

79

499.

879

0.00

0

9,99

7.58

0 9,

997.

580

0.00

0 1

52,2

46.4

80

154,

307.

080

2,06

0.60

0

Fig. 4 Cross

Fig. 5 Gully

7653

20+

00

Ch

G

B

G

Ch

Gully Ero

s sections at 0 m

y bed profile: (a

76.5

32

75.1

58

73.2

4

69.5

2

6346

8

0+00

0+20

0+40

0+60

0+80

hainage (m)

Gully bed levels (m)

Bed slope (%)

Gully bed levels (m) Bed slope (%)

44.2

02

43.5

14

42.7

19

42.2

84

0+56

0

0+58

0

0+60

0

0+62

0 hainage (m)

osion Study a

m, 200 m, 400

a) 0 m to 560 m

63.4

68

60.8

61

58.5

64

56.1

26

0+10

0

0+80

0+12

0

0+14

0

39.2

66

41.8

64

41.3

41

41.4

26

0+64

0

0+66

0

0+68

0

0+70

0

and Control:

m, 600 m and

m; (b) 560 m to

56.7

36

55.9

16

49.9

96

48.6

66

4821

0

0+16

0

0+18

0

0+20

0

0+22

0

0.017%

40.6

71

40.5

11

39.9

96

39.4

16

0+72

0

0+74

0

0+76

0

0+78

0

A Case Stud

800 m.

(a)

(b)

o 960 m.

48.2

10

48.0

06

47.9

48

47.2

39

0+24

0

0+26

0

0+28

0

0+30

0

0.017%

39.3

81

39.0

31

38.5

91

38.3

21

0+80

0

0+82

0

0+84

0

0+86

0

y of Queen E

46.8

09

46.6

89

46.4

04

44.0

39

0+32

0

0+34

0

0+36

0

0+38

0

37.9

71

37.6

11

37.1

96

36.8

91

0+88

0

0+90

0

0+92

0

0+94

0

Ede Gully in B

45.7

14

46.4

07

46.1

04

45.3

64

0+40

0

0+42

0

0+44

0

0+46

0

36.5

76

0+96

0

Benin City

44.2

84

44.2

84

42.5

04

44.5

37

0+48

0

0+50

0

0+52

0

0+54

0

1275

44.2

02

0+56

0

5

Tabl

e 3

Mon

thly

rai

nfal

l dist

ribu

tion

for

Beni

n C

ity fr

om 2

001-

2010

, in

mm

.

Yea

r Ja

n.

Feb.

M

ar.

Apr

. M

ay

Jun.

Ju

l. A

ug.

Sep.

O

ct.

Nov

. D

ec.

Tota

l M

ean

Max

M

in

2001

0.

00

14.6

0 11

1.40

18

1.77

27

3.80

20

2.00

22

4.30

65

.70

296.

90

147.

80

39.9

0 0.

00

1,55

8.10

12

9.84

27

3.80

0.

00

2002

0.

00

16.0

0 16

5.40

19

6.50

22

2.60

35

1.40

48

9.10

14

0.40

14

8.30

11

1.40

10

8.40

12

.90

1,96

2.40

16

3.53

48

9.10

0.

00

2003

0.

00

9.70

78

.70

200.

80

189.

20

272.

10

515.

90

149.

20

300.

70

241.

10

162.

30

0.00

2,

119.

70

176.

64

300.

70

0.00

20

04

0.00

18

.80

97.6

0 26

7.30

32

3.50

38

8.40

35

9.10

12

8.40

38

3.40

12

8.10

70

.80

4.90

2,

170.

30

180.

86

388.

40

0.00

20

05

61.6

0 44

.40

110.

40

115.

20

266.

00

308.

20

294.

70

191.

30

379.

40

236.

20

124.

70

0.00

2,

132.

10

177.

68

379.

40

0.00

20

06

12.8

0 49

.40

157.

50

136.

50

137.

70

352.

70

569.

20

127.

10

393.

00

150.

30

23.3

0 22

.80

2,13

2.30

17

7.69

56

9.20

12

.80

2007

7.

50

51.1

0 10

8.90

25

9.70

29

8.30

35

1.70

44

5.30

82

.40

402.

80

292.

20

39.9

0 11

.50

2,35

1.30

19

5.94

44

5.30

7.

50

2008

0.

00

38.9

0 42

.40

211.

40

182.

40

385.

30

434.

80

275.

30

410.

70

384.

20

29.8

0 0.

00

2,39

5.20

19

9.60

43

4.80

0.

00

2009

5.

60

40.6

0 14

8.20

10

6.30

17

8.40

25

0.20

17

4.30

72

2.40

36

9.10

29

1.70

15

4.80

1.

10

2,44

2.40

20

3.53

72

2.40

1.

10

2010

3.

20

37.7

0 10

9.40

38

6.30

36

8.30

27

7.70

50

6.10

25

7.10

33

6.70

13

8.40

10

2.10

91

.30

2,61

8.30

21

8.19

38

6.30

3.

20

Tota

l 90

.70

321.

20

1,12

9.90

2,

061.

70

2,44

0.20

3,

139.

70

4,01

2.80

2,

139.

30

3,42

1.00

2,

121.

40

860.

00

145.

00

21,8

82.0

0 1,

823.

50

4,38

9.00

37

.50

Mea

n 9.

07

32.1

2 11

3.00

20

6.17

24

4.02

31

3.97

40

1.28

21

3.93

34

2.10

21

2.14

86

.00

14.5

0 2,

188.

20

182.

35

438.

90

3.75

M

ax

61.6

0 51

.10

165.

40

386.

20

368.

30

388.

40

569.

20

275.

30

410.

70

384.

20

162.

30

91.3

0

M

in

0.00

9.

70

42.4

0 10

6.30

13

7.70

20

2.00

17

4.30

65

.70

148.

30

111.

40

23.3

0 0.

00

Fig. 6 Rainf

Fig. 7 Slope

loss was esti

area of 126,4

Recent re

and collapse

the gully hea

area caused

The geote

the soil is s

irreversible a

tendency fo

slumping esp

high rainfall

Arising fro

Gully Ero

fall IDF (intens

stabilization t

imated to be 3

480 m2 which

sults (Table 1

e of gully wa

ad as a result

by the storm

echnical inve

silty clay. Er

and it is reaso

r widening o

pecially durin

l (from May-S

om the above,

osion Study a

sity duration fr

technique.

393,069.580 m

h is equivalen

1) showed tha

alls continue

of active eros

runoff.

estigation resu

rosion in thi

onable to assu

of gully to o

ng the period

September).

the following

and Control:

requency) curv

m3 over a sur

nt to 3.108 m3

at under—cut

to occur aro

sive action in

ults revealed

s type of so

ume that there

ccur due to

d characterize

g control meas

A Case Stud

ve for Benin C

rface 3/m2.

tting

ound

n this

that

oil is

e is a

wall

d by

sures

wer

that

catc

to a

stab

cutt

mov

redu

gull

and

y of Queen E

City.

re proposed fo

Redesign a

t will be able

chment area,

appropriate di

Implement

bilization of t

ting;

Provide che

vement and

ucing high r

ly bed and th

d deepening;

Ede Gully in B

or the Queen E

and provide a

e to carry all t

and channel

ischarge poin

appropria

the gully hea

eck dams alon

transportati

runoff and f

hereby protect

Benin City

Ede gully eros

adequate drai

the storm run

them away fr

nts;

ate reclam

ad to prevent

ng the gully b

ion of erod

flow velocitie

ting the bed f

1277

sion:

inage system

noff from the

rom the gully

mation and

further head

bed to control

ded soils by

es along the

from incision

7

m

e

y

d

d

l

y

e

n


1278

Provide adequate slope stabilization along the

gully walls using gabions as retaining walls at the base

and rock boulders placed on the gully walls, which

have been trimmed to appropriate slopes. In between

these boulders are planted vetiver grass and bamboo

trees with firm roots to hold the soil in place against

erosion. The boulders are held down by steel meshes,

which will later be removed as the grasses and trees

begin to grow. Typical cross section of the proposed

method is shown in Fig. 7.

5. Conclusions

Based on the findings from the studies conducted,

the following conclusions were drawn:

The likely cause of this gully is as a result of the

river bank eating back into the land, and this has been

accelerated by the way the accumulated runoff from the

catchment enters into the river;

The recent abrupt growth and expansion of the

gully can be attributed to the change in the rainfall

pattern in the region, which has been caused by climate

change resulting from global warming;

Apart from the head region of the gully, other

regions such as the middle and the tail regions have

already stabilized. Thus, only the head region is active;

The results from the geotechnical studies

conducted on the soil showed that the soil is susceptible

to water erosion;

The existing drainage facilities are inadequate to

contain the runoff coming from the catchment;

Control measures such as slope stabilization for

the gully walls around the head region, redesigning and

upgrading of the existing drainage system, provision of

gully control structures at the head region, and

provision of check dams at specific intervals along the

gully bed, can be used to prevent the gully from

expanding.

References

[1] I.I. Obiadi, C.M. Nwosu, N.E. Ajaegwu, E.K. Anakwuba,

N.E. Onuigbo, E.O. Akponomu, et al., Gully erosion in

Anambra State, south east Nigeria: Issues and solution,

International Journal of Environmental Sciences 2 (2)

(2011) 795-804.

[2] J.O. Ehiorobo, O.C. Izinyon, Measurement and

documentation for flood and erosion monitoring and

control in the Niger Delta States of Nigeria,

www.fig.net/pub/fig2011 (accessed Jan. 1, 2013).

[3] O.C. Ezezika, O. Adetona, Resolving the gully erosion

problem in south-eastern Nigeria: Innovation through

public awareness and community-based approaches,

Journal of Soil Science and Environmental Management 2

(10) (2011) 286-291.

[4] C. Valentin, J. Poesen, L. Young, Gully erosion: Impacts,

factors and control, Catena 63 (2005) 132-153.

[5] K.O. Adekalu, I.A. Olorunfemi, J.A. Osunbitan, Grass

mulching effect on infiltration, surface runoff and soil loss

of three agricultural soils in Nigeria, Bioresource

Technology 98 (4) (2007) 912-917.

[6] S.C. Teme, P.O. Youdeowei, Geotechnical investigations

for design of foundations for erosion and flood control

structures at Unwana Beach, Afikpo, Ebonyi state,

South-Eastern Nigeria, in: Proceedings of 5th

International Conference on Case Histories in

Geotechnical Engineering, New York, USA, Apr. 13-17,

2004.

[7] J. Poesen, Gully topology and gully control measures in

the European loess belt, in: S. Wicherek (Ed.), Farm Land

Erosion in Temperate Plains and Hills, Elsevier,

Amsterdam, 1993, pp. 221-239.

[8] J. Poessen, J. Ngchtergaele, G. Verstraeten, C. Valentin,

Gully erosion and environmental change: Importance and

research needs, Catena 50 (2003) 91-133.

[9] G. Verstraeten, J. Poesen, The nature of small-scale

flooding, muddy floods and retention pond

sedimentation in central Belgium, Geomorphology 29

(1999) 275-292.


Analysis of the Antenna’s Setup Errors at the Global

Navigation Satellite System Measurements

Evangelia Lambrou

School of Rural and Surveying Engineering, National Technical University of Athens, Athens 15780, Greece

Abstract: Today, the GNSS (global navigation satellite system) is used for more complicate and accurate applications such as monitoring or stake out works. The truth lies in the fact that in the most of the times not enough attention is paid to the antenna’s setup. Usually, gross errors are found in the antenna’s centering, leveling and in the measurement of its height, which are significant. In this paper, a thoroughly analysis of the above mentioned errors is carried out. The influence of these errors in the calculation of the X, Y, Z Cartesian geocentric coordinates and the φ, λ, h ellipsoid geodetic coordinates of a point P on the earth’s surface, is analyzed and is presented in several diagrams. Also a new convenient method for the accurate measurement of the antenna’s height is presented and it is strongly proposed. The conclusions outline the magnitude of these errors and prove the significance of the antenna’s proper setup at the accurate GNSS applications.

Key words: GNSS antenna’s height, centering and leveling errors, GNSS antenna’s setup.

1. Introduction

The GNSS (global navigation satellite system)

measurements are used for the determination of

accurate coordinates of points (of the order of some

mm), which belong to monitoring networks, or to

stake out applications [1-3].

It is well known that the human intervention during

the measurements is minimum by using the satellite

positioning systems. Namely no sighting is needed, as

when total stations are used.

However, a receiver must be put at a selected point,

the antenna must be centered and leveled properly and

the antenna’s height must be measured by using a

usually simple tape.

Are all the above-mentioned activities carried out

with the proper manner? Mistakes, gross or random

Corresponding author: Evangelia Lambrou, assistant

professor, research fields: development of methodology for the determination of astronomical coordinates, precise determination of undulation n of geoid, interconnected systems, e-geodesy, observations via internet, check and calibration of geodetic instruments (geodetic metrology), development of methodologies for precise measurements, geometric documentation of technical and natural structures. E-mail: [email protected].

errors, which could be done, when a GNSS antenna

placed will be proved significant. Today the minimum

uncertainties, which are expected, require major

attention to the measurement of antenna’s height and

to the antenna’s centering and leveling in order to

acquire correct measurements.

In the following paragraphs, the aforementioned

errors are analyzed, in order to determine the

magnitude of the error that each one adds in the

calculation of the geodetic coordinates φ, λ and h or

the geocentric coordinates X, Y, Z of a point.

As the errors that will be discussed are of the order

of some centimeters, it may be considered that the

earth is a solid sphere with radius R. This admission is

adequate for the analysis.

2. The Antenna’s Height

As the ellipsoid is the reference surface of the

GNSS system, is useful to remind that the height of

the antenna (ah) is measured along the plumb line

instead of the geodetic normal as ought to be

measured (Fig. 1).

Eq. (1) gives the correct antenna’s height:

DAVID PUBLISHING

D

Analysis of the Antenna’s Setup Errors at the Global Navigation Satellite System Measurements

1280

Geoid

plump line

vertical to the ellipsoid

ε

Ellipsoid

P

P'antenna's phase center

Fig. 1 The measurement of the antenna’s height along the plumb line.

cos)( measuredhh aa

(1)

where, ε is the deviation of the vertical, at the specific

point.

As the deviation of the vertical (ε) is of about some

arcsec and a mean antenna’s height is of about 1.5 m,

it’s obvious that this correction is insignificant.

Thus, when the coordinates of a point P on the

earth’s surface, (XP, YP, ZP) are needed the coordinates

at a point P´, (XP, YP, ZP) (Fig. 1) are initially

calculated. The point P´ corresponds to the electric

phase center of the antenna.

Using the fundamental equations for the

transformation of φ, λ coordinates to X, Y, Z [4] but

simplify them considering that the earth is a sphere

with radius R, then the coordinates of the point P´ can

be calculated: coscos)( '' pp hRX

sincos)( '' pp hRY

(2)

sin)( '' pp hRZ

It is pointed out that the geometric height h of P´

includes the antenna’s height measurement ah:

hpp ahh '

(3)

Namely, the component of the antenna’s height ah

in relation to the geocentric coordinate system X, Y, Z

ought to be subtracted from the coordinates XP, YP,

ZP in order to the desired coordinates XP, YP, ZP of

the point P be calculated by combining Eqs. (2) and (3).

Assuming that the error of the antenna’s height

measurement is e, then the coordinates of point P will

be: coscos)(' eaXX hpp

sincos)(' eaYY hpp

(4)

sin)(' eaZZ hpp

The errors pXm ,

pYm , pZm , that correspond to the

coordinates XP, YP, ZP, due to the error e are as

follows: coscos em

pX

sincos em

pY

(5)

sin empZ

The magnitude of each component depends on the

position of the point P on the earth’s surface, namely,

its approximate latitude and longitude.

It is noted that, this error does not influence the

ellipsoid coordinates φ, λ of point P but only the

geometric height h, which bears the total error.

Figs. 2-4 illustrate the change of the components

pXm , pYm ,

pZm , for an error e equal to 1 cm in relation

to the position φ, λ of the point P on the earth’s surface.

As it is depicted in the diagrams, pXm and

pYm

fluctuate from 0 mm to 10 mm. Their absolute values

are minimized at φ = ± 90o at the earth’s poles and they are maximized near the equator. Also

pXm

decreases, when λ increases as pYm rises. On the

contrarypZm , becomes 0 at the equator and it

maximizes at the poles.

3. Accurate Measurement of the Antenna’s Height

The measurement of the antenna’s height using a

tape, while it is on a tripod or a pillar is not an

accurate procedure. So, some manufacturer are

accompanied their receivers with a special equipment

for the antenna’s height measurements [5]. Also

guidelines are given for the proper measurement of an

antenna’s height [6, 7].

A mistake of some millimeters or a little more can

be very easily read. Additionally, the proper

positioning of the tape on the antenna’s hook or on the

ε


1281

-10

-8

-6

-4

-2

0

2

4

6

8

10

-90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90

Geodetic Latitude (o)

mXp(m

m)

λ=0 λ=30&330 λ=60&300 λ=90&270

λ=120&240 λ=150&210 λ=180

Fig. 2 The error pXm for e = 1 cm.

-10

-8

-6

-4

-2

0

2

4

6

8

10

-90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90


mYp (m

m)

λ=0&180 λ=30&150 λ=60&120 λ=90

λ=210&330 λ=240&310 λ=270

Fig. 3 The error

pYm for e = 1 cm.

-10

-8

-6

-4

-2

0

2

4

6

8

10

-90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90


mZp (m

m)

Fig. 4 The error

pZm

for e = 1 cm.


1282

antenna’s band or on the antenna’s bumper is doubtful.

Moreover, the zero point of the tape, most of the times,

is not in the proper position. Finally, the misreading of

the tape must be taken into consideration as a gross error.

Therefore, for special GNSS applications which

need the maximum accuracy, it is proposed that the

measurement of the antenna’s height should be carried

out by using the spirit leveling method as follows:

(1) Before the antenna’s setup at a selected point P,

it is essential for a staff to be put on it (Fig. 5a);

(2) A digital level is placed and is leveled at a close

distance of about 3-5 m. The indication i on the staff

is then registered;

(3) Next, the tripod with the tribrach and the

adaptation base of the antenna is placed, centered and

leveled at point P;

(4) The staff is put on the surface of the adaptation

base where the antenna will be mounted, and a second

indication j is registered (Fig. 5b).

The antenna’s height ah is calculated easily by the

equation:

jia h (6)

By using the above procedure, the true vertical

measurement of the antenna’s height ah from the

bottom of its mount is calculated. It is also indicative

that the distance d between the antenna’s electric

phase center and the bottom of the antenna’s mount, is

accurately known (md = ± 0.1 mm) as it is given by

the manufacturers in order to be used in the process of

calculating the measurements.

The accuracy that i and j can be measured is of the

order of mi = mj = ± 0.1 mm by using a system digital

level—barcode staff. Thus, applying the variance

covariance low in Eq. (6), the total uncertainty of an

antenna’s height measurement is determined by:

mmmmmmm jia h2.015.022 (7)

The above analyzed procedure proved easy to apply

and extremely accurate as it required less than 5 min

to be implemented and protects against gross or

systematic tape-reading errors.

4. The Centering and Leveling Errors

The centering error is defined as the deviation of

the projection along the plumb line of the antenna’s

phase center from the desire point P (Fig. 6). In

correspondence to the centering error, the leveling

error has the same definition due to the wrong

leveling of the antenna.

Moreover, in this case, the measurement of the

antenna’s height holds an additional error. These

errors present the deviation of the main vertical axis of

the antenna, from the plumb line, which intersects the

desire point P.

Despite the human carelessness during the set up of

the antenna, these errors are also caused either due to

a tribrach bad check or to a complete overlook of a

required check.

The antenna’s centering and leveling errors both

exist on a horizontal plane, which is perpendicular to

the plumb line at point P. Both are gross errors and it

is difficult to discover and define the true vector,

which represent them.

The result of these errors is a vector PP with an

unknown absolute value. This vector ecl (Fig. 6) starts

from the desired point P and has a random geodetic

azimuth A.

Considering that the earth is a solid sphere with a

mean radius R = 6,371 km then this vector can be

analyzed in two components, one along the meridian,

namely σφ, and the other along the parallel, namely

σλ. The components σφ and σλ, as presented in Fig. 6, are:

Aem cl cos)( or ''cos

''

R

Aecl (8)

Aem cl sin)( or ''cos

sin''

R

Aecl (9)

where,

A is geodetic azimuth of the vector PP(ecl);

ecl is absolute value of the error;

ρ´´ is 206,265.

The σφ fluctuates from ecl, if A = 0 or A = π, to zero

if A = π/2 or A = 3π/2. The opposite is valid for σλ.


1283

j

i

P P

Fig. 5 The accurate measurement of an antenna’s height.

e

P

P''

poin

t'sm

erid

ien

cl

A

σλ

σφ

Equator

P

σ φ

P``

σ λ

Fig. 6 The analysis of the vector of centering and leveling error.

As previously mentioned, it is difficult to determine

the azimuth A of this vector which varies from 0 to 2π.

Thus the mean value m of this error ecl (centering and

leveling) along the meridian according to the Eq. (8)

can be calculated as:

n

Aem cl

2

2 )cos( (10)

where, n is the elementary step dA of azimuth A from

0 to 2π.

dAn

2 (11)

According to Eq. (11) the following integral can be

formed:

dAAem cl

2

0

22 )cos(2

1 (12)

By solving the integral of Eq. (12), the following

result comes out:

dAAem cl

2

0

22 )cos(2

1

dAA

edAAe clcl

2

0

22

0

22

2

2cos

2

1cos

2

1

22cos

2

1

2

1

2

1 22

0

2

0

2 clcl

eAdAdAe

(13)

The same result arises if Eq. (9) used for the

calculation of the mean error along the parallel. Thus

a mean value of centering and leveling error is

(a) (b)

Centering point Centering point

Level Level

σφ

σλ


1284

equal to:

2cle

m (14)

The following chart (Fig. 7) depicts the mean error

at φ and λ due to an error ecl of the antenna’s centering

and leveling.

This error can also be analyzed in the geocentric

coordinates system according to the Eq. (2). It adds an

error mcl in the geocentric coordinates XP, YP, ZP of

the desired point P as follows: )cos()cos(coscos)( pclXp hRm

)sin()cos(sincos)( pclYp hRm

)sin(sin)( pclZp hRm (15)

Consequently, clXpm , clYpm , clZpm , are the corrections

that should be applied to the calculated geocentric

coordinates at P in order to achieve the correct

coordinates at point P. It is pointed out that σλ does

not add error to the Z coordinate of point P. Also the

accurate value hP is insignificant compared to the

earth’s radius for the calculation of the errors clm by

using Eq. (15).

Figs. 8 and 9 illustrate the clXpm , clYpm , for an error

σφ = σλ =1 cm ≈ 0´´.0003 for all combinations of φ and

λ, assuming that hP = 0.

Fig. 10 illustrates the clZpm for an error σφ = σλ =

1 cm ≈ 0´´.0003 and σφ = σλ = 5 cm ≈ 0´´.0015, for

all combinations of φ and λ, assuming that hP = 0.

Figs. 8 and 9 look like nomograms as they are

enough complicated. The error clm takes zero value

as well as the maximum value 10 mm, for every

longitude but for different latitudes.

0

5

10

15

20

25

30

35

40

45

0 10 20 30 40 50 60 70

ecl (mm)

Mean error in φ,λ (mm)

Fig. 7 The mean error at φ and λ in mm.

-12

-10

-8

-6

-4

-2

0

2

4

6

8

10

12

-90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90


mclX

p (m

m)

λ=0 λ=30 λ=60 λ=90 λ=120 λ=150

λ=180 λ=210 λ=240 λ=270 λ=300 λ=330

Fig. 8 The clXpm for an error σφ = σλ = 1 cm ≈ 0´´.0003.

M

ean

erro

r in

φ, λ

(m

m)


1285

-12

-10

-8

-6

-4

-2

0

2

4

6

8

10

12

-90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90


mcl

Yp (m

m)

λ=0 λ=30 λ=60 λ=90 λ=120 λ=150

λ=180 λ=210 λ=240 λ=270 λ=300 λ=330

Fig. 9 The clYpm for an error σφ = σλ =1 cm ≈ 0˝.0003.

-55

-50

-45

-40

-35

-30

-25

-20

-15

-10

-5

0

-90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90


mcl

Zp(m

m)

mcl=1cm mcl=5cm

Fig. 10 The clZpm for an error σφ = σλ = 1 cm ≈ 0˝.0003 and σφ = σλ = 5 cm ≈ 0˝.0015.

5. Conclusions

The inaccuracies of the antenna’s setup are

disregarded, as no works on this subject were carried

out worldwide. Nevertheless, it is proven by the

aforementioned analysis, that significant error may

change the final coordinates, which are calculated by

the GNSS systems.

An error in the antenna’s setup, affects the

geocentric coordinates X, Y, Z, the ellipsoid

coordinates φ, λ, and the h of a point P.

The transmitted error e in the measurement of the

antenna’s height at the X, Y, Z geocentric coordinates

depends on the position of the point on the earth’s

surface, namely its latitude and longitude. So, this

error in each coordinate fluctuates from 0 to the

maximum value e.

The error in the measurement of an antenna’s

height does not affect the φ, λ coordinates but only the

geometric height h of the point.

To avoid this error, a special prototype procedure

for the measurement of antenna’s height is proposed

in order to eliminate this error to ± 0.2 mm. This

method is efficient, accurate and easy to perform. It is

evaluated as worthy, despite the fact that more

instrumentation is needed.

The centering and leveling error ecl needs more


1286

caution as it affects both the geocentric and the

ellipsoid coordinates. This error has a mean value of

about 2

cle , which is significant for many applications.

The real magnitude and the azimuth of the ecl is very

difficult and almost impossible to be known.

Therefore, careful laboratorial checks of the tribrach

should be carried out before each campaign.

Otherwise, special manufactured pillars or bases for

precise centering should be used in order to eliminate

this error at the level of ±0.1 mm.

The above analysis is significant for monitoring

networks or infrastructure stake-outs, as the

uncertainty of the calculated coordinates by the GNSS

may be largely augmented.

References

[1] M.S. Rawat, V. Joshi, B.S. Rawat, K. Kumar, Landslide movement monitoring using GPS technology: A case

study of Bakthang landslide, Gangtok, East Sikkim, India Journal of Development and Agricultural Economics 3 (5) (2011) 194-200.

[2] J.F. Zumberge, M.B. Heflin, D.C. Jefferson, M.M. Watkins, F.H. Webb, Precise point positioning for the efficient and robust analysis of GPS data from large networks, Journal of Geophysical Research: Solid Earth 102 (2012) 5005-5017.

[3] S. Shimada, Y. Bock, Crustal deformation measurements in central Japan determined by a global positioning system fixed-point network, Journal of Geophysical Research: Solid Earth 97 (1992) 437-455.

[4] G. Bomford, Geodesy, 4th ed., Clarendon Press, Oxford,

1980.

[5] Leica Geosystems Solutions Centers Website, http://www.leica-geosystemssolutionscenters.com/Site/Instrument%20PDF's/GPS%20Systems/Viva/VivaGNSS_EquipList.pdf (accessed Jan. 1, 2013).

[6] D.E. Wells, W. Beck, D. Delikaraoglou, A. Kleusberg, E.J. Krakiwsky, G. Laschappele, et al., Guide to GPS Positioning, University of New Brunswick, Fredericton, New Brunswick, Canada, 1986.

[7] A. Fotiou, C. Pikridas, GPS and Geodetic Applications, Ziti Publications, Thessaloniki, Greece, 2006.


Evaluating Land Surface Changes of Makassar City

Using DInSAR and Landsat Thematic Mapper Images

Ilham Alimuddin1, 2, Luhur Bayuaji2, Rohaya Langkoke1, Josaphat Tetuko Sri Sumantyo2 and Hiroaki Kuze2

1. Department of Geology, University of Hasanuddin, Makassar 90221, Indonesia

2. Center for Environmental Remote Sensing, Chiba University, Chiba-Shi 863-8522, Japan

Abstract: Urban growth has been a major issue in environmental monitoring and changes occurred on land surfaces have been monitored by applying remote sensing as well as ground measurement. Most major cities in the world have experienced land subsidence phenomena on some parts of them due to the load of development and modernization. Excessive extraction of groundwater for the needs of industry has led to the condition where the water table drops, and this can possibly trigger subsidence, as observed in

Indonesian cities. In this study the authors have shown that the application of DInSAR (differential interferometric synthetic aperture radar) technique using Japanese Earth Resources Satellite-1 Synthetic Aperture Radar JERS-1 SAR data can reveal subsidence

conditions in the studied Makassar city area. Landsat TM (thematic mapper) images were used to evaluate the change of land cover during the observation period of 1994-1999. Makassar is flat, covered mainly by alluvium deposit that is vulnerable to the load of constructions, and volcanic formations which is porous and will easily be degraded by groundwater extraction. It is found that mostly the subsidence has occurred in the western part of the city, including the industrial district, reclamation area, trading center area and the seaport area. The ground survey has indicated that high human activity exists in every point of subsidence. It is likely that various human activities such as ground water pumping and construction work should have affected the local subsidence phenomena in Makassar, as in the case of other large-scale cities in Indonesia.

Key words: DInSAR, JERS-1, surface changes, urban growth, Landsat TM.

1. Introduction

The impact of modernisation often appears as

urbanization. It is natural that where a centre of

civilization exists, the flow of development will gather

therein. It is needed to study how one city grows by

accommodating the impact of civilization and to

examine if the growth is safely sustainable for the

people occupying the area. As the number of

population increases, more and more agricultural,

shrub, and even swamp land areas are changed into

industrial and construction areas, especially in rural

areas surrounding the former city boundary. In

addition to the increase in the usage of groundwater,

such land cover changes can result in shortage of

Corresponding author: Ilham Alimuddin, master of

geographic information systems, research fields: concept and application of remote sensing and geographic information systems for geomorphological and geological changes. E-mail: [email protected].

water supply in the hydrologic cycle. In urban areas,

one of the particular concerns is the occurrence of

land subsidence that will in turn cause flood.

Makassar, the capital city of the South Sulawesi

Province, in relation to this issue has been a target of

urbanization since the old era.

Remote sensing methodologies on the other hand

are useful for the study of land subsidence, as seen in

their applications to some of the big cities worldwide

[1-3]. One of the most recent studies is the one over

China by Perissin and Wang in 2011 [4] using the

advanced technique of PS InSAR (persistent scatterer

InSAR). The recent advancement of remote sensing

technology has made it possible to map detailed

terrain conditions ranging from local, regional to

global scale with specific use and accuracy. The SAR

(synthetic aperture radar) sensor onboard JERS-1

satellite provides the ability to map the earth surface

DAVID PUBLISHING

D

Evaluating Land Surface Changes of Makassar City Using DInSAR and Landsat Thematic Mapper Images

1288

topography and deformations independently of

weather conditions despite any cloud cover or solar

illumination. SAR records simultaneously the

intensity and phase of the signal reflected from the

surface.

The phase is related to the travel time of the radar

pulse between the spacecraft and the ground. The

interferometric combination can be used to derive

DEMs (digital elevation models) for an area [5].

Various methods have been employed, with the latest

methods using the DInSAR [6] and Permanent

Scatterer Insar [7]. Cities in Indonesia have been

investigated using this technique was Jakarta [8, 9],

Semarang [10, 11] and Bandung [12, 13]. The present

paper evaluates the application of DInSAR technique

by measuring the dimension of land subsidence

phenomena that has occurred in the city of Makassar,

which has been one of the notable centers of south

eastern Asian civilisation as an urban hub since 16th

century. The DInSAR investigation of the Makassar

city has not been sought before, to the best of people’s

knowledge.

Makassar city covers an area of 175.77 km2 divided

into 14 sub districts. The city lies on the geographic

coordinate of 119°18'27,97"-119°32'31,03" East

Longitude and 5°00'30,18" -5°14'6,49" South Latitude.

The landform is relatively flat, classified as alluvial

plain with topography levels from 0-21 m above sea

level (Fig. 1a). Geologically, the city is covered by

four types of formation, Camba Volcanic Formation,

Salo Kalumpang Volcanic formation (which mainly

consists of fine sediment clastic of volcanic eruptive

rocks but mostly eroded), a small area of Limestone

Tonasa Formation and alluvium formation deposit as

recent weathered material. In general, the authors can

find three types of rock units, basalt, tuff and breccia

derived from volcanic origins and sediment deposit

like fine to coarse sand (Fig. 1b).

The population of the city was 0.94 million in 1990,

which increased to 1.2 million in 2010 [14], causing

the increased use of both land surface and ground

water. The rapid urbanization has made Makassar as a

centre for economic development in eastern part of

Indonesia. On the basis of the statistics of Makassar

Fig. 1 Study area: (a) Makassar city boundary ; (b) The geological map of the area.

(a) Study area

(b) Geology map

Indonesia


1289

City, population has been increasing due to the

development and urbanization. Hence, the situation

continues while people long for development to have

better lives. The population increase triggers

industries to develop new areas for business and

construction. When the governmental control is

limited in the rural area surrounding the city, the

agricultural, shrub and even swamp spaces are

developed, which in the future could generate land

subsidence due to the extraction of water through

wells. This mechanism has been suspected as the

major cause of the subsidence of the urban land

phenomena.

2. Data and Methodology

This research utilized eight scenes of JERS-1 SAR

images of level 0 covers a swath area of 75 km2 in

descending modes with 35.5 degree of incident angle

with acquisition date ranging from 1993 until 1998,

but the area focused for the subsidence study is only

175.77 km2.

DInSAR analysis was performed using

SIGMASAR software developed by JAXA [15]

combined with ENVI and ArcGIS software for

implementing the GIS analysis. The DInSAR

processing uses two pass interferometry to create an

interferogram from two pairs of intensity (single-look,

complex, SLC (single look complex) images.

Subsequently, the differential interferogram is

flattened and unwrapped to obtain the deformation

map of the subsidence area, while evaluating the depth

of subsidence from the interferogram. The flow chart

of the DInSAR process can be seen in Fig. 2 [16, 17].

Based on the visual observation of Landsat images,

urban development can also be seen from historical

changes of the land cover. Landsat image acquired in

September 1999 was used to create landuse map of

Makassar in 1999 and Landsat image acquired in 1994

to create landuse map 1994. The load of development

can be seen from the conversion of rice paddies, dry

field and homogenous forest into business, services,

and industry area. This conversion can obviously be

observed in the northern part of the city. The city

expansion also can be seen from the settlement and

landuse change that bring more urban concentration to

the area. The subsidence analysis is also supported

with Landsat TM acquired in 1994 and Landsat ETM

acquired on September 20, 1999. These Landsat

images have been chosen in line with the acquisition

dates of the SAR images. These images can be seen in

Fig. 3. Field campaigns were conducted in September

2009 and January 2011 with handheld GPS (global

positioning system) instruments. All supporting data

are georeferenced to WGS (World Geodetic System)

1984 GIS (Geographic Information System) platform.

This can be observed on the northern part and the

southwest near the coastal line. The new high rise

apartments, hotels and public facilities were

constructed on this part of the city. Industrial area

where warehouses and factories were built along the

highway burdens the less compacted soil of coastal land.

Fig. 2 Schematic flow chart of DInSAR processing.

DTM DTM

Slave Master DEM

Simulated SAR

DEM Co-registration

Fringe removal

Differential interferogram

Phase unwrapping

Geocoding

Deformation map

SAR processing

Image co-registration

Interferogram generation

Phase unwrapping

Geocoding


1290

Fig. 3 Intensity image: (a) Landsat TM_FCC_432 acquired on Aug. 29, 1994; (b) Landsat ETM_FCC_432 acquired on Sep. 20, 1999; (c) Intensity Image of JERS-1 data acquired on 19941011; (d) JERS-1 intensity image acquired on Aug. 19, 1998.

3. Results and Discussion

As mentioned earlier, the authors processed eight

datasets of JERS-1 SAR to create seven pairs to

DInSAR images. Due to satellite orbital errors and

influence of atmospheric conditions during the

acquisition and considering the baseline difference of

the two image used as master and slave images, three

of the pairs have shown incoherence hence cannot be

further analysed. In Fig. 4, the authors can observe

colour coding patterns on the four images in some

areas that show some consistencies while other areas

display bands of interferometry noises. The authors

have chosen the pair image of 1995/1996 to be

analysed in detail, as shown in Fig. 5, the coherence

image in Fig. 5a, a subset image in Fig. 5a and the

deformation image in Fig. 5a.

The subset of the image that shown the indication

of slight subsidence at the western part of the City of

Makassar was then overlaid with high resolution

image to confirm the subsidence location supported

by the pictures taken from the ground survey in Fig. 5.

The colour coding estimates a slight subsidence of

5-15 cm per year in particular area especially with the

load of heavy settlement.

The authors have shown that the application of

DInSAR technique using JERS-1 data can reveal

subsidence conditions in the study area. Mostly the

subsidence occurred in the northern part of Makassar

city during the time interval studied here, though the

population density in northern part is lowest among

the entire city regions. Industrial district, reclamation

area, trading centre area, international airport and the

(a) (b)

(c) (d)


1291

Fig. 4 DInSAR processing images on the LOS (line of sight ), all datasets are on descending mode: (a) pair of 1995/1996; (b) Pair of 1996/1997; (c) pair of 1997/1997; (d) pair of 1997/1998, later image is master and earlier image is slave.

Fig. 5 DInSAR processing images of Makassar City: (a) coherence image of 1995/1996; (b) DInSAR Image pair of 1995/1996 images; (c) the deformation image after the unwrapping process.

seaport are built in this region. The centre of the

subsidence with the subsidence-affected coverage area

can also be estimated easily. It has been found that the

subsidence occurred in separated regions with

different land usage. Nevertheless, the ground survey

has indicated that high human activity exists in every

point of subsidence.

Various human activities such as ground water

pumping and construction working should have

affected the local subsidence phenomena in Makassar,

as in the case of other large-scale cities. The main

cause of subsidence in Makassar has not been

revealed because of the complex feature of the

phenomena. However, the result of the present study

strongly suggests that the human activity and land use

alteration are influencing the geomorphological

changes in this city. Field campaign conducted in

September 2009 revealed some locations that indicate

the incidence of land subsidence and the fact that

some parts of the city are having load of building

(a) (b)

deep shallow

(c)

-5.9 cm 0 5.9 cm

(a) (b)

(c) (d)

Antenna direction S

atellite direction


1292

Fig. 6 Focus on deformation image of Tamalate area and surrounding overlaid with Quickbird image acquired on May 6, 2007.

Fig. 7 Pictures taken from the field observation indicating the occurrences of land subsidence, picture code correspond with the location in Fig. 6, red arrow indicates subsidence.

construction that make the city experience of slight

movement of its earth surface.

New building construction of warehouses can be

seen in picture P1 taken in the area of Tallo, New

housing and modern apartment as well as community

business complex in P2. Evidence of subsidence can

be seen in Paotere, in Panakkukang, in Mariso and in

Tamalate. On one of the main road, the soil load can

P3

P1

P2

P4

P1 P2

P3 P4


1293

be a thickness of 15-20 cm (Figs. 6 and 7).

4. Conclusions and Future Study

DInSAR method is used to estimate subsidence

phenomena which has been derived and applied in this

study. Continuous information of subsidence area will

be useful for urban maintenance and urban

development field, as one important factor for

planning and construction works. So far, only few

subsidence-related studies have been carried out using

SAR data over urban area. The authors have tried to

apply JERS-1 SAR although not all pairs can give

good coherence due to the baseline and atmospheric

aspects.

The authors have successfully implemented the

DInSAR processing technique in measuring the

dimension of the land subsidence. The incidences in

some areas show evidence of from 5-15 cm of

subsidence shown by field observation conforming the

result of DInSAR processing images. Although the

main cause of subsidence in Makassar has not been

revealed because of the complex feature of the

phenomena, the result of the present study strongly

suggests that the human activity and land use

alteration are influencing the geomorphological

changes in this city.

In the future, as the City of Makassar will be

growing larger and denser, it needs monitoring that

even slight changes on its surface can be detected as it

is prone to seasonal disaster such as floods and

subsidence. With this DInSAR method, the authors

hope to utilize newer SAR datasets to retrieve the rate

of subsidence happened.

References

[1] D. Raucoules, C. Colesanti, C. Carnec, Use of SAR interferometry for detecting and assessing ground subsidence, Comptes Rendus Geosciences 339 (2007) 289-302.

[2] R.S. Chatterjee, B. Fruneau, J.P. Rudant, P.S. Roy, P.L. Frison, R.C. Lakhera, et al., Subsidence of Kolkata (Calcutta) City, India during the 1990s as observed from space by differential synthetic aperture radar

interferometry (D-InSAR) technique, Remote Sensing of Environment 102 (2006) 176-185.

[3] N. Phien-wej, P.H. Giao, P. Nutalaya, Land subsidence in Bangkok, Thailand, Engineering Geology 82 (2006) 187-201.

[4] D. Perissin, T. Wang, Time-series InSAR applications over urban areas in China, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing 4 (1) (2011) 92-100.

[5] H.A. Zebker, J. Villasenor, Decorrelation in interferometric radar echoes, IEEE Transactions on Geoscience and Remote Sensing 30 (1992) 950-959.

[6] L. Bayuaji, R.F. Putri, J.T. Sri Sumantyo, Combination of L,C and x-Band SAR data for continuous monitoring of land deformation in urban area by using DInSAR Technique, in: Proceeding of International Conference on Space, Aeronautical and Navigational Electronics, Incheon, 2012.

[7] A.H. Ng, L. Gea, X. Li, H.Z. Abidin, H. Andreas, K. Zhang, Mapping land subsidence in Jakarta, Indonesia using PSI (persistent scatterer interferometry) technique with ALOS PALSAR, International J. of Applied Earth Observation and Geoinformation 18 (2012) 232-242.

[8] L. Bayuaji, J.T. Sri Sumantyo, H. Kuze, ALOS PALSAR D-InSAR for land subsidence mapping in Jakarta, Indonesia, Canadian J. Remote Sensing 36 (1) (2010) 1-8.

[9] H.Z. Abidin, H. Andreas, I. Gumilar, M. Gamal, Y. Fukuda, Y.E. Pohan, et al., Land subsidence of Jakarta (Indonesia) and its relation with urban development, Nat Hazards 59 (2011) 1753-1771.

[10] M. Marfai, L. King, Monitoring land subsidence in Semarang, Indonesia, Environmental Geology 53 (2007) 651-659.

[11] A.M. Lubis, M. Sato, N. Tomiyama, N. Isezaki, T. Yamankuchi, Ground subsidence in Semarang-Indonesia investigated by ALOS PALSAR satellite SAR interferometry, Journal of Asian Earth Sciences 40 (2011) 1079-1088.

[12] J.T. Sri Sumantyo, M. Shimada, P.P. Mathieu, H.Z. Abidin, Long-term consecutive DInSAR for volume change estimation of land deformation, IEEE Transactions on Geoscience and Remote Sensing 50 (1) (2012) 259-270.

[13] H.Z. Abidin, H. Andreas, I. Gumilar, D. Murdohardono, Y. Fukuda, On causes and impacts of land subsidence in Bandung Basin, Indonesia, Environ Earth Sci. 68 (2013) 1545-1553.

[14] Makassar Statistics Bureau, BPS (Badan Pusat Statistik),

Kotamadya Makassar, Makassar in Figures, Annual

Report of 1993-1998, and 1999. (in Indonesian and

English)


1294

[15] M. Shimada, , Verification processor for SAR calibration and interferometry, Adv. Space Res. 23 (8) (1999) 1477-1486.

[16] P.A. Rosen, S. Hensley, I.R. Joughin, F.K. Li, S.N. Madsen, E. Rodriguez, et al., Synthetic aperture radar

interferometry, Proceedings of the IEEE 88 (3) (2000) 333-382.

[17] H. Fan, K. Deng, C. Ju, C. Zhu, J. Xue, Land subsidence monitoring by D-InSAR technique, Mining Science and Technology 21 (2011) 869-872.


The Industrial Heritage and the New Architecture:

Teaching, Researching, Designing the Place Identity

Monica Bruzzone and Roberta Borghi

Department of Civil Engineering and Architecture (DICATEA), University of Parma, Genoa 16142, Italy

Abstract: The new architecture may provide unusual opportunities for the abandoned areas involved by former industrial processes, both in the city centers and in the landscape. In fact, it may create new centralities and give new collective function for deprived areas. The case study of the architectural and educational project for a new museum park devoted to the technique and the science in the Apennine’ s landscape near Parma (Italy) may give an interesting point of view about the role of the teaching and the research of the architecture in the former industrial heritage, and to avoid the abandonment and the pauperization of the territory around.

Key words: Identity, industrial heritage, architecture, architecture design studio, teaching, research.

1. Introduction

The architecture may provide new opportunities for

the places development, particularly in those urban or

rural landscapes where the end of a productive

tradition have established heavy losses, both from a

social point of view, with the gradual loss of a local

identity—well represented by that specific technique

or industry—and from a environmental point of view,

with the creation of large urban voids and the presence

of a disused industrial heritage, often rich in quality.

In this case study, the new architecture may

represent a important way of giving opportunities to a

deprived area by introducing new functions or new

central points and by giving, as well, a new social

identity for the place.

The industrial heritage and the large areas deprived

by the abandonment of factories, workshops, mines or

pits after the end of the production, may represent at

the same time the remains of an ancient technical

identity and the opportunity for designing a new

identity, giving the territories who hosted the industry

a new cultural or productive life, starting from both

the physical and immaterial rests of a lost past.

Corresponding author: Monica Bruzzone, Ph.D., research

fields: architecture, architectural, design, industrial heritage and places identity. E-mail: [email protected].

The new architectural design has to consider,

therefore, a wide number of variables to produce an

effective new architectural project.

First of all, it is necessary to make a deep research

about the characteristics of the places and the needs of

its community, so to interpret the true values of the

old industrial vocation and to understand what

memories you have to save and how can you represent

them by the new architecture. Then it is necessary to

ask which functions can you assign to the site, in

order to turn a negative polarity in a new public

centrality, where it can be pleasant to live, to work, to

study, to attend cultural events or just to “stand and

stare”. A wrong design process may deliver the place,

once again to oblivion and neglect. At the same time,

it is important to consider how the research, the

teaching and design, may be complementary for

rethinking the former industrial heritage and for

rediscovering the local identities.

The Research Group AMR/APR [1], working with

the Department of Civil Engineering and Architecture

(DICATeA), University of Parma, is experiencing

since many years how the rural areas and the small

towns of the Emilian Appenines may be requalified by

a new kind of architecture. As well the main objective

of this study is to demonstrate how to contribute to the

DAVID PUBLISHING

D

The Industrial Heritage and the New Architecture: Teaching, Researching, Designing the Place Identity

1296

development of a former industrial area by the new

functional, social and architectural project, and how a

new centrality for the community or, if you want, a

new “piazza” may give new values for a wider area,

creating new kinds of use for that place.

2. The Industrial Heritage and the Role of the Architecture

It is important to note that the main references of

these studies can be found in some Italian researches

of the 1970s and 1980s and in the definition—or

better in the re-definition—of some specific cultural

values based on the delicate balance between the work

of men and the landscape development [2].

The interpretation of the so called “Italian

condition” by the researcher Emilio Sereni, Lucio

Gambi and Giulio Bollati [3], aims for instance, at

defining new interests for the rural areas as actors of

the architectural process as well as the metropolitan

areas. A concept already developed in Italy by

Giuseppe Pagano [4] just before the Second World

War.

The connections between the men’s work and the

physical characteristics of the territory are also

deepened in 1970s by the Italian geographer Lucio

Gambi. He clarifies that the relationship between the

place and the human’s work is an essential goal in the

development of any community. The man settles in

areas with good characteristics for the life and the

production, and then he modifies those places and

makes them appropriate for the lifestyle of the

community and the techniques of settlement.

As opposed to the Paul Virilio theory of

“crepuscular dawn” [5] as a condition of

de-territorialisation and loss of cultural reference

points, the “sense of place” defined by Gambi [6] may

represent an effective tool for the design process in the

landscape. As well, the most recent definition of

“family relationship between men and land” by

Salvatore Settis [7] may be a good starting point for a

new way of understanding the relationships between

the countryside and the new architecture. The former

industrial sites on the Emilian Appenines may be

interesting examples of how represent a new heritage

to discover, by the creation of new centralities to the

development of wider areas.

2.1 The New Architecture: Tool for the Development

of the Former Industrial Sites

The Research Group “Architecture Museums

Networks”, is working since many years on the

subject of redeveloping little centres and parts of

landscape through the insertion (or better you could

say the “infill”) of a new architectural polarity inside

the landscape. The new project may be a public place

or a collective building or just a square, but it may

have the special skill of interpreting the social needs

of the community and creating a new centrality for

this specific “horizon of territory” or “unity” of

landscape itself. So you aim at building a new identity

by the construction of new characters for that specific

society starting from the ancient memory of the site.

The project is deepened by the collaboration with

some important institution for the local heritage such

as the IBC (Istituto per i Beni Artistici, Culturali e

Naturali), that is the institute for Cultural Heritage of

the Region Emilia Romagna, in Italy. Some of this

studies became architectural projects or bachelor’s

thesis by the members of the research group.

2.2 The Officine Reggiane, Reggio Emilia Italy

The ancient Officine Meccaniche Reggiane is a

former industrial site where, since the first years of the

20th century there was a wide production of railways

components and artillery projectiles. The industry

became famous in the late 1930s for the production of

the fighter aircrafts. After the end of the production, in

the early 1950s, the wide site of the Reggiane became

a urban void. The research group aimed firstly with

the degree thesis by Roberta Borghi (Fig. 1), at

redesigning the whole site of the Reggiane, building a

new centrality with services, cultural activities, work


1297

Fig. 1 A model of the Officine Meccaniche Reggiane, design by architect Roberta Borghi, year 2008.

spaces and public spaces for the city of Reggio Emilia.

The starting point of the design process was the

interpretation of a peculiar ancient axis and streets,

designing a museum dedicated to the Officine

Meccaniche Reggiane, a way of transmitting the

memories of a still strong identity.

2.3 The Glass Museum and Science Centre Bormioli

in Parma

The “Bormioli Rocco & Figlio” is one of the oldest

glassware in the city of Parma. Around the first

workshop, built in 1854, it was created a new

neighbourhood inhabited, in the beginning, by the

workers families. Now the neighbourhood is a part of

the city of Parma, extended further beyond the old

perimeter of the nineteenth century. After the end of

the production, the ancient factory became a wide

urban void in the middle of a residential district of

Parma and today it aims at becoming a new centrality

for Parma as a polycentric city. The recent proposal

by the architect Luca Vacchelli, aim at creating a new

cultural polarity to give the area a functional

characterization, a kind of specialization. The study

for this area is commissioned by the owners: The

“Bormioli Rocco” and it will be evaluated by the

municipality of Parma.

The Science Centre (Fig. 2) is a missing cultural

polarity for Parma, and at the same time the

environments of the old factory, with galleries and

Fig. 2 Sketch of the science center and glass museum Bormioli, design by architect Luca Vacchelli (2010-2012).

long and narrow halls, is very adequate for the

needing of a contemporary science centre, with

interactive boxes and large-scale reconstructions. As

well the older building is dedicated to the Glass

Museum Bormioli: a place for the memory of the lost

identity of the factory.

3. The Petroleum Museum Park in Fornovo di Taro, Parma

The project of a Petroleum Museum Park (Fig. 3)

for the little town of Fornovo di Taro, nearby Parma is

an important case study where teaching, researching

and designing are considered three important parts of

a common process. This study is now starting an

operating phase after receiving funding by the MIUR,

the Italian Ministry of University and Research, based

on the annual programs proposed by the Italian Law

6/2000. In this part of the architectural design process,

the research group aims at giving new life and new

characters to a former industrial site, with a

multimedia exhibit and a design of guidance in the

park, so the architecture may be the most important

Fig. 3 The workshops and the forge of Vallezza, photo by Andrea Ciampolini ©.


1298

opportunity for the redevelopment of a wider part of

landscape in a pleasant part of the Apennines.

The research program is based on an agreement

between the University of Parma, the Municipality of

Fornovo and the Oil Company Gas Plus Italiana SpA,

owner of the areas. The aim of the research is to

recover the industrial and the natural heritage in one

of the oldest oilfields in Italy (1860-1970), for both

tourist and educational purposes. The mine,

developing a local self extractive system called

“metodo Fornovo”, was intensively exploited in the

early 20th, and almost exhausted during the autarkic

period of the Fascism, when it was one of the focal

points for the supply of crude oil for the army. The

mine is also the place where it was established the

Società Petrolifera Italiana, now called Ente Nazionale

Idrocarburi, one of the most important operators of

hydrocarbons in Italy.

Some oil wells and natural gas wells have remained

active up to 1970, until the production became

uneconomic. Since that time, after the reclaiming of

the wells and some industrial plants, the ruins of the

workshops, the forge, the power station, the pumping

stations in the wood and the miners village, have lost

their former function and now they remain as well as

rests: objects trouvé immersed in the clay hills of

Fornovo. The dissemination of the extraction

techniques and the memory of the ancient oilfield,

may play an important role in the educational program

of the Province of Parma, where there are not

museums or study centers devoted to disseminate the

sciences and the techniques.

As a verification process of an evolving theoretical

subject, the Architecture Design Studio (Second year

of the Degree in Architecture) is working on the

architectural and urban design of these depressed

areas by the introduction of a new architecture as a

new public centrality able to give a new identity and

new social functions to the place.

The work is divided in two different phases. In the

first semester a preliminary approach to the project, is

devoted to transmit some cultural issues and some

positions of the architectural debate. In the second

semester, each student have to apply these notion to a

design process connected with the place of the

Oilfields of Fornovo di Taro.

In the first part, students have to learn by basis

elements of the architectural process as well as the

construction and the assembly, the cut or the

excavation of solid corps, making exercise of creating

a new architectural space by the addition or the

subtraction of matter.

This is a way to investigate how the architectural

design should begins from theoretical premises and

the personal poetry, but it may become architecture

only through the “contamination” with the materials

and the techniques. The first exercise is the design of a

small exhibition pavilion with a dimension of 6 m × 6

m × 6 m, for the exhibition of an only artwork, as

suggested in the literary essay: “The museum in the

third millennium” by Eco [8]. The creation of a 1:20

scale maquette of the small building becomes

necessary to learn the three-dimensional role of the

architectural projects (Fig. 4).

The second exercise is the redrawing of two

different existing buildings: an exhibition pavilion and

a most complex building chosen between lists of

architectural models of 20th century (Fig. 5).

The second semester is focused on the project of a

Petroleum Museum Park in the valley of Fornovo,

Fig. 4 The architectural models of the first semester.


1299

Fig. 5 The oil pavilion: A new exhibitions pavilion for the area of Vallezza.

seat of the ancient oilfield. Students are called to

reflect on different scales of the design: from the

landscape to the building, up to the exhibition design.

Students are divided in groups of two or three

people. Each group is called to design a park museum

with the aim of enhancing the place by deepening

some specific architectural and functional themes,

such as a meeting place for tourists and for the bikers,

pathways and roots trough the industrial rests, but also

a study place for disseminating the identity of the

former oilfield (Fig. 6).

After deepening the park, each group may design

the new cultural centrality with a museum devoted to

the technique and the scientific culture, a study centre

with a small auditorium, a library and a laboratory for

the children’s activity, but also a place for guests,

such as a little diffused hotel (in the little town of

Vallezza, the former miner’s village), or a guesthouse

for tourists and schools visiting the place. In the last

month of the year each group deep an only building in

scale 1:100.

This approach to the design process aim at giving

the students the special skill of “seismographs” of the

needs of the place having a direct approach with

inhabitants and better understanding the place’s

problems.

In parallel with this teaching process, also useful to

raise public awareness of, and with funds obtained

Fig. 6 A sample of the architectural design studio works. The museum park of Fornovo. A masterplan and the design of the cultural center in the Cantiere Respi, the heart of the former industrial site, by the student Valentina Manente (Architectural Design Studio 2-2013).


1300

from the Ministry, it is processing the project of a

small pavilion or a multimedia installation by bringing

in schools and public institutions in order to

dissemitate the scientific culture connected with the

oil and the memory of a lost cultural identity, and to

trigger a virtuous cycle of rigeneration of this area, as

well as of Fornovo di Taro, by increasing the value of

an important industrial activity forgotten today

and by giving a new centrality to a nice part of the

Appenines very interesting but very little used

today.

The new centrality should be able to generate a new

complexity and liveability of the place, hosting

different activities, planning diversified and easily

accessible areas, and becoming, therefore, a strategic

element for a wider part of the landscape.

4. Conclusions

Teaching about the design process and the

architectural composition to young students in their

first years of university can be a good opportunity to

experiment a kind of teaching method based on three

areas of teaching.

The first area is the theory. The main theoretical

issues and the ideas of the architectural debate may be

discussed with the students in order to communicate

them the complexity of the architectural problems

trough the centuries, and to stimulate the critical

thinking. The second area is the technique. Only

through the contamination between the architectural

ideas and the materials, forms and techniques you can

appreciate the discipline of architecture as a concrete

fact and something three-dimensionally accomplished.

But in addition to the theory and the technique, the

discipline of architectural composition is also

composed by the poetry. This third subject may be

suggested or alluded or commented on by a teacher,

who wants to communicate students the importance of

this topic through the architectural debate and through

every design process, but it is a matter quite delicate

and fragile. As well can not certainly teach it, because

it may became a part of each student’s cultural

baggage.

Acknowledgments

The authors would like to thank the MIUR (Italian

Ministry of Research), the Municipality of Fornovo di

Taro (Parma) and the Gas Plus Oil Company, for the

financial support to the research. Also we would like

to thank the AMR Research Group and the department

Dicatea—University of Parma.

References

[1] Reconnecting the Design Research with Actual Demands of the Territory, AMR (Architecture Museums Network) and APR (Architecture Landscape Network), University of Parma, 2005.

[2] M. Bruzzone, L. Serpagli, Le radici anonime dell’abitare moderno, Ph.D. Thesis, University of Trento, Franco Angeli, Milano, 2012.

[3] R. Romano, C. Vivanti, I caratteri originali, Encyclopeda, Torino, 1972.

[4] G. Pagano, G. Daniel, Architettura Rurale Italiana, Quaderni della Triennale, Hoepli, Milano, 1936.

[5] P. Virilio, Crepuscular Dawn, Semiotext(e), NY, USA, 2002.

[6] L. Gambi, I valori storici dei quadri ambientali, in: Storia d’Italia, Einaudi, Torino, 1972.

[7] S. Settis, Paesaggio, Costituzione, Cemento, La battaglia

per l’ambiente contro il degrado civile, Torino, 2010.

[8] U. Eco, Il museo del terzo millennio, Bilbao, June 25,

2001.


Surface Soil Effects Studies Based on H/V Ratios of

Microtremors at Kingston Metropolitan Area, Jamaica

Walter Salazar1, Lyndon Brown2 and Garth Mannette1

1. Seismic Research Centre, The University of the West Indies (UWI), St. Augustine, Trinidad and Tobago

2. Earthquake Unit, The University of the West Indies (UWI), Mona, Kingston, Jamaica

Abstract: The authors performed single mobile microtremor measurements at 218 sites at KMA (Kingston Metropolitan Area) with the objective of estimating the amplification effects due to the earthquake ground motion on the surface geology. The Fourier transform was applied to the most stationary parts of the triaxial wave motion recordings for each individual site and applied the traditional Nakamura technique, namely, the horizontal to vertical spectral ratio (H/V) to retrieve the predominant shear wave period of vibration of the soil profiles above the bedrock. The results yield predominant long periods of about 3.0-4.0 s in the port area and the waterfront, 1.0-2.0 s in the central part of Kingston, 0.3-1.0 s in Portmore and very stiff soil conditions in the surrounding area of the city. The results coincide fairly well with previous geological studies in the region, geotechnical data in boreholes, gravimetric measurements and strong motion recordings, suggesting a high degree of amplification of ground motion in the whole period range of engineering interest. Additionally, the authors obtained the liquefaction vulnerability factor Kg proposed by Nakamura based on the H/V ratio of microtremors. The results suggest that the port area, the waterfront and the Port Royal are highly susceptible to liquefaction. Finally, the authors obtained fundamental periods of vibration based on microtremor measurements on the roof and the basement of four important buildings in the KMA and indicated future lines of research employing ambient noise measurements on structures. Key words: Microtremors, Rayleigh and S-waves, amplification factor, fundamental period of vibration.

1. Introduction

Several researches documenting the destructiveness

of several seismic events have established the

pervasive influence of the sedimentary deposits on the

preferential distribution of damages, such distribution

appears to correlate well with the degree of

amplifications caused by the surface geology, the

authors can then regard the local distribution of the

ground shaking intensity as a phenomenon closely

related to the filtering effects of the soil profile [1, 2].

Several studies have shown that Nakamura’s technique

[3] for estimating shear wave resonant periods is a

robust method that can yield useful information

regarding the soil profile of a site in the near surface. In

this work, the authors study the site effects in KMA

Corresponding author: Walter Salazar, doctor of

engineering, research fellow, research fields: earthquake engineering and engineering seismology. E-mail: [email protected].

(Kingston Metropolitan Area) by performing single

mobile microtremor measurements at 218 sites. In the

first section, the authors introduce the surface

geological setting of KMA based on available

references for the city, secondly, an explanation of the

methodology involved in the collection and processing

of the microtremor data is presented and then outlined

the theoretical background of the Nakamura technique

to retrieve the quasi-transfer function of the soil profile.

From this study, a new isoperiod contour map and a

3-D basin depth for the KMA have been proposed. The

quasi transfer functions obtained by the microtremors

are validated with available gravity, boreholes and

strong motion data for the KMA. Finally, the authors

assessed the liquefaction potential based on their

microtremors recording, the water table level and the

ground level shaking proposed by the new seismic

hazard maps for Jamaica presented in the previous

issues.

DAVID PUBLISHING

D

Surface Soil Effects Studies Based on H/V Ratios of Microtremors at Kingston Metropolitan Area, Jamaica

1302

2. Geological Setting of Kingston Metropolitan Area

The Liguanea Plain is a quaternary alluvial fan of the

Hope River that drains the mountains to the northeast

of Kingston forming the southern boundaries of the

KMA. It consists of poorly sorted sands and gravels

interspersed with layers of clay and sand. Occasionally,

boulders of volcanic rock and conglomerate are also

found [4]. The fan rises gently from sea level at

Kingston harbour to more than 200 m elevation at

Mona in the northeast, where it meets the Hope River at

the base of the mountain range, the northern limits of

the KMA used in this study. Few wells dug in the fan

sediments have reached bedrock, hence the shape of

the underlying basement and the thickness of the

alluvium are not well known. To better constrain depth

to basement rock, a gravity survey was conducted

along two transects across the Liguanea Plain [5]. The

results indicate a gradual deepening to 500-600 m at

the Kingston waterfront with a more uniform depths of

300-400 m with undulations found along an east-west

profile. The average shear-wave velocity of the fan

sediments was estimated from well logs to be 320-495

m/s and the basement rock was assumed to be Miocene

Limestone. The surrounding hills to the northwest in

Stony Hill and on the Limestone plateaus of Long

Mountain all sit on Tertiary Limestone, these are areas

of recent uplift and show high levels of fault

escarpments, to the northeast are the highly jointed

clastic sedimentary and volcanoclastic rocks of the

Wagwater Formation showing recent slope failure

deposits where currently new developments are

continuously being built on the colluvial slope deposits

of former landslippage.

The southern extension of the tombola that drains

alluvial deposits along the Palisadoes now exists as one

continuous landmass previously existing as individual

cays that have progressively been joined with some

amount of anthropogenic interference. The westward

extension of the Palisadoes is located at the old

buccaneering city of Port Royal. This once infamous

city that was destroyed in the major earthquake M 7 [6]

of 1692 is made up of discontinuous coral reefs

connected by sands and gravels deposited by longshore

drift from the estuaries of the Hope, Cane, Yallahs and

Morant Rivers to the east of Kingston. The

predominant deposits are loose sand deposits which are

highly susceptible to liquefaction due to its shallow

water table and poorly compacted deposits. The

northwest limit of the KMA in the area of Stony Hill

sits at an elevation of 1,400 ft. with the underlying

rocks of the White Limestone plateau of the eastern

extension of the Troy Formation.

Most of the waterfront sections of the city are built

on engineered fill on which sits significant sections of

the infrastructure of the city. There are also some

sections of artificial fill or man-made ground which are

non-engineered, which forms parts of downtown

Kingston, Kingston harbour, the industrial zone

leading to the airport, and also in the west area of the

Newport where the activity is again modified by

engineered fill, as shown in Fig. 1.

Most of the rocks in the surrounding mountain

overlooking the plain are extensively faulted. The

southern part of the Wagwater Trough and

westernmost extension of the Plantain Garden fault

system separates the Liguanea Plain from these

outcrops. The northwest trending Wagwater Fault at

the northern limits of the Liguanea Plain is associated

with many micro-earthquakes [7].

On average over 200 earthquakes are recorded

annually by the Jamaica Seismograph Network. These

events have epicenters both locally (on-land and within

the coastal waters) and regionally (outside of the local

region but within 400 km from the Jamaica

Seismograph Network). At least 10 of these

earthquakes are described as felt events. Current

earthquake frequency data from the earthquake unit at

UWI (University of the West Indies) Mona show the

highest levels of seismicity is associated with the

eastern part of Jamaica (Kingston St. Andrew, Portland

& St. Thomas) accounting for over 75% of the earthquake


1303

Fig. 1 General geological map of Kingston Metropolitan Area and microtremor points surveyed (black solid circles). The polygon includes the wave motion of microtrermors and the horizontal to vertical H/V spectral ratios presented in Figs. 5 and 6. The crosses (X) denote boreholes indicating the depth of the bedrock or the maximum depth reached (>). The red triangles denote strong motion stations (SMS1 and SMS2).

events on the island. The new probabilistic seismic

hazard maps developed for Jamaica at rock site

conditions presented in previous issues confirm that

KMA is subjected to a moderate/high seismicity based

on a peak ground acceleration of 0.24 g for 475 years

return period and spectral accelerations for periods of

0.2 s and 1.0 s yielding levels of 1.05 g and 0.16 g

respectively for 2,475 years return period.

3. Theoretical Background of H/V Ratios of Microtremors

Microtremors are a general term for constantly

existing minute vibrations at the surface of the ground

with body and surface waves being the main

component of microtremors. Microtremors show

specific characteristics of the surface geology, and are

periodic and contain the amplification characteristics

of the soil, which is often referred to as site-effect. The

periodic characteristics of microtremors are similar to

the ones during earthquakes, however, the amplitude of

microtremors is quite small caused by human activity,

machinery, traffic, etc.. Due to the close relation

between the nature of microtremors and the

fundamental dynamic behavior of the surface soil

layers, these small vibrations are useful and also well

known in the field of earthquake engineering. To assess

Chalk Non-limestone Recrystallized Rubbly Yellow limestone


1304

the transfer functions, the authors used the traditional

method of Nakamura, the horizontal to vertical spectral

(H/V) ratio.

While studying the characteristics of microtremors,

Nogoshi and Igarashi [8] found a conspicuous

similitude of the horizontal to vertical spectral ratios

(H/V) of microtremors to that of Rayleigh waves. This

led them in the first instance to suggest Rayleigh waves

as the main component of microtremor recordings.

This constitutes the origin of the horizontal to vertical

spectral ratio technique applied in the estimation of the

amplification of the horizontal motion in the presence

of surface layers using microtremors [9, 10].

Nakamura [3] revisited this method and brought it back

to the engineering community as non-reference site

technique providing a theoretical interpretation in the

form of his semi-quasi transfer spectrum model

incorporating the effects of Rayleigh and S-waves in

his formulation. Nakamura’s formulation of the H/V

spectral ratio departs from the assumption that the

vertical component of motion reaches the surface

without undergoing significant amplification within

the frequency range of interest in engineering, thereby

retaining the characteristics of the horizontal motion at

the engineering bedrock. Nakamura [3] proved the

validity of this crucial assumption at the Tabata and

Kanonomiya sites in Japan for the usual frequency

range of practical interest in engineering, namely, from

0.125 Hertz to 10 Hertz (0.1 s to 8.0 s). The authors

define Hi(f) and Hb(f) as the surface and engineering

bedrock horizontal Fourier amplitude spectrum of

microtremors, respectively. If f denotes the frequency

of ground motion, then the authors can express the site

effects function Gi(f) at a site i, by applying the

following expression:

( ) ( ) ( )f f fbi iG H H (1)

It seems worth noting that although dealing with

microtremor recordings, Eq. (1) results in a transfer

function formulation quite similar to that proposed by

Borchedt [11] for earthquake ground motion

recordings. In their original formulation, Nakamura [3]

assumed that the energy of microtremors comprises

both body and surface waves, and that the surface

sources generate Rayleigh waves equally affecting the

horizontal and vertical components of motion [9]. If the

authors assume that the vertical motion due only to

body waves undergoes no amplification, then the

authors can express the effect of the Rayleigh waves on

the vertical motion ES (f) as follows:

( ) ( ) ( )f f fs i bE V V (2)

According to this development, ES yields 1.0 in the

absence of Rayleigh waves, whereas values over 1.0

indicate the effect of Rayleigh waves. The next step in

this formulation comprises the vertical and horizontal

components of motion assuming a similar effect of

Rayleigh waves on both. On these premises, the

formulation of the horizontal to vertical motion

spectral ratio (H/V) aims at eliminating the Rayleigh

wave’s effect via calculation of the ratio Gi(f)/Es(f): ( ) ( ) ( )( ) ( )

( ) ( ) ( ) ( ) ( )

/*

/

f f ff f

f f f f f

ii b i b

i iS b b

H H VG HH V

E V V V H (3)

According to the previous assumptions, at the

engineering bedrock, the ratio Hb(f)/Vb(f) equates 1.0

within a relatively wide period range. Accordingly, the

authors can estimate the soil transfer function by taking

the Hi(f)/Vi(f) ratios of the surface recordings.

4. Microtremors Survey and Data Processing

The authors performed microtremors survey at

Kingston Metropolitan Area (Fig. 1) in November

2011, June 2012 and November 2012. A total of 218

measurements with an average of 500 m-1 km spacing

was made employing a triaxial Tokyo Sokushin 24 bit

sensor, model CV-374A with a flat response between

0.1 Hz to 10 Hz (Fig. 2) and a recording system of 100

samples per second, the sensors measured micromotion

in terms of acceleration.

The following six steps were adopted to perform the

surveys and to analyse the data (Fig. 3):

(1) The authors tried to make the measurement

whenever in a silent environment for at least 5 min


1305

Fig. 2 Transfer function for the Tokyo Sokushin Sensor CV374-A (Courtesy of Isamu Yokoi).

Fig. 3 Flowchart showing the methodology for data collection and digital signal processing.

at each location (trying to maintain the survey, interval,

however there are some locations where the authors

had to collect in the closest possible location relative to

this interval), since the instrument can easily record

surrounding noise such as heavy traffic. These are

reflected in spikes on the records that can perturb the

periodic features of the microtremors. The horizontal

sensors were located with north-south and east-west

orientations (magnetic north);

(2) Samples of 20 s of the stationary parts of the


1306

recording were selected initially for processing;

(3) For each sample, the authors applied a baseline

correction that targets the elimination of the noise

associated with the unknown zero-level line associated

with long period components, this serves to remove the

signal offset responsible for constant shifts of all

acceleration values. The Fourier transform was then

applied to the records and with the band pass raised

cosine filter. The authors selected the low and high

cutoff frequencies in the filter according to the dynamic

amplification factor (flat response) provided by the

sensor manufacturer (Fig. 2);

(4) The authors applied the inverse Fourier

transform to obtain the corrected acceleration time

history for each record;

(5) For each selected stationary part, the authors

computed the resultant Fourier acceleration amplitude

spectrum and the correspondent uncertainties for the

horizontal and vertical components of motion. The

authors smoothed the spectra applying a Parzen

Window with a bandwidth of 0.4 Hz;

(6) Finally, the authors calculated the horizontal to

vertical spectral ratio (H/V) employing the resultant

vector of the orthogonal north-south and east-west

components of motion and averaging the results for all

the stationary parts selected for each record, the

maximum and minimum ratios were computed as well.

The authors identified the peak in the H/V ratio and

located it in the geographical information system. They

plotted the spectra for 0.1 s to 8.0 s coinciding with the

period range of interest for earthquake engineering

practice.

Fig. 4 Horizontal to vertical spectral ratio (H/V) for different lengths of sampling data: microtremor measurement recorded at 2011/11/20 13:38:50 with coordinates 17°59.301' N, 76°47.855' W (Top); microtremor measurement recorded at 2011/11/28 11:28:34 with coordinates 17°59.6082' N, 76°46.5924' W (Bottom). The maximum, minimum and the mean of the H/V ratios are presented for each recording.


1307

It should be noted that an iterative procedure is

sometimes necessary to improve the resolution and to

reduce the uncertainties in the results especially when

long period ground motion is predominant in the

spectrum (Fig. 4). Stationary samples of 20 s

sometimes are not enough for the resolution of the

spectrum above periods of 1.0 s: in this case, the

authors increased the duration of the samples to 60 s

and repeated the procedure for (ii) to (vi) in Fig. 3. In

other cases, the authors repeated the measurements

recording for 15 min in those locations where long

period ground motions appeared and increased the time

of the samples and also employing 60 s to make the

signal processing scheme.

4.1 Analysis and Interpretation

The authors present in Fig. 5 the horizontal wave

motion of microtremors for the transverse section from

north to south depicted in Fig. 1. It is clear that the

characteristic of microtremors varies considerably

along KMA in terms of amplitude and period of motion.

Generally, the amplitude and the period increase from

the mountain region in the north toward the south at the

shore in the port area, the amplitude varies from 0.1

cm/s2 to 2.0 cm/s2 and the period from 0.1 s to 3-4 s.

The authors present the plots of the H/V ratios for the

same points in Fig. 6 and plot the predominant periods

for the whole city in Fig. 7. From east-west, there is a

minor change in the periods of the unit.

Along the Liguanea Basin and at the eastern part of

the waterfront, the authors observe an average period T

of 2.0 s confirming the presence of the thick alluvial

deposits on KMA basin (Fig. 7). The average shear wave

velocity (VS) of the fan sediments is estimated from well

logs to be 320-495 m/s (410 m/s) [5]. Taking the

fundamental period T in seconds of a soil profile equal to: 4

( )S

HT s

V (4)

Inverting Eq. (4) for H yields an average depth of ≈

200 m in the Liguanea Plain above the Miocene

Limestone (see depth of the boreholes in Fig. 1), which

is considered here as the engineering bedrock. The

microtremor results primarily coincide with the general

geology setting of the basin where poorly consolidated

alluvial deposits with the deepest boreholes down to

depth at least 200 m, Aspinall and Shepherd [12]

suggest layers of sand retained in the shallower parts

with clays comprising deposits of the deeper parts.

The shear wave velocity VR for the limestone is equal to:

RV

(5)

where, μ is the rigidity modulus and ρ is the density.

Taking typical values for the limestone of μ = 24 GPa,

ρ = 2.7 g/cm3 yields a VR = 943 m/s. Employing an

optional Eq. (6) to find the depth of the bedrock H

employing microtremors is as follows [13]:

4

R

S g

VH

A F (6)

where, AS is the ratio VR/VS and Fg is the predominant

frequency based on microtremors. Setting VR = 943

m/s for the limestone and taking AS = 943/410 = 2.30

and Fg as 0.50 Hz (T2 = 2.0 s) yields a depth H = 205 m.

Note that Eq. (6) is equivalent to Eq. (4), however, the

computed AS ratio determines the contrast between the

rock and the soil that is related to the sharp peak and the

through observed in the H/V ratios (Fig. 6c).

The longest periods of about 3.0 s to 4.0 s are

observed in the port area to the west of KMA and the

sand spit that connects Portmore and KMA, presumably

reclaimed land areas with the water table is commonly

close to the surface. The results coincide with a soil

profile depth of about 310-410 m as a result of natural

sedimentation and landfill. Also, Aspinall and Shepherd

[12] suggest that the deepest part may exceed 300 m in

this area. The general trend of the increasing depth of the

sediments from north to south in KMA is also confirmed

by the gravimetric survey performed by the National

Disaster Research [5] yielding thickness of the alluvial

deposits ranging from 100 m to 600 m.

The authors found along the Palisadoes spit different

periods of vibrations of the soil profiles, at the western

part in Port Royal area the periods yield 1.0-2.0 s


1308

-0.2

0

0.2

-0.2

0

0.2

-0.40

0.4

-0.4

0

0.4

-0.8

0

0.8

-0.8

0

0.8

-0.8

0

0.8

-2

0

2

-0.80

0.8

Acc

ele

ratio

n (c

m/s

2)

-0.8

0

0.8

-2

0

2

-2

0

2

-0.80

0.8

-2

0

2

(1) 2011/11/22 17:22:13

(2) 2011/11/22 16:57:02

(3) 2011/11/21 15:49:34

(4) 2011/11/21 15:23:35

(5) 2011/11/19 18:32:34

(6) 2011/11/19 18:06:42

(7) 2012/11/27 16:20:32

(8) 2012/11/27 15:52:47

(9) 2011/11/19 13:56:54

(10) 2011/11/20 16:13:10

(11) 2011/11/25 14:17:51

(12) 2012/11/29 17:42:58

(13) 2011/11/20 17:10:16

(14) 2012/11/29 17:15:36

-0.4

0

0.4

-0.8

0

0.8

-0.4

0

0.4

0 4 8 12 16 20Time (s)

-0.4

0

0.4

(15) 2011/11/24 18:35:41

(16) 2012/11/28 18:41:47

(17) 2012/06/23 18:04:57

(18) 2011/11/24 18:04:12

Fig. 5 Wave motion microtremors for the N-S component inside the polygon shown in Fig. 1.


1309

suggesting a loose intermediate soil depth profile of

about 100-200 m. The shortest periods in the range of

0.3-0.6 s were found at the Norman Manley

International Airport possibly due to compaction works

related to the construction of the airport, however, soft

soil conditions were found at the western edge of the

runway with a period of 1.5 s, suggesting a different

degree of soil compaction during the construction

process of the airport. At the eastern edge of the spit in

the Harbour View, the authors found again period of

1.5 s related with the sediments deposited by the Hope

River.

The spectral shape of the H/V ratios and the absolute

acceleration Fourier spectra introduce an insight of the

wave propagation of microtremors (Fig. 8): the

sediments above bedrock behave as a high-pass filter

allowing the Rayleigh waves to propagate in the

surface layers, however, the Rayleigh waves can not

(a)

(b) (c)

Fig. 6 Horizontal to vertical spectral ratio (H/V) for the points inside the polygon depicted in Fig. 1, the numbers next to the ratios correspond to the same numbers depicted in Fig. 5, the authors computed the geometrical mean for the horizontal component of motion, T1 is nearly 1/2T2 indicating a high contrast between the sediments and the basement rock in KMA.

1,000

100

10

1


1310

propagate in the period range of the predominant

period of the surface layers T2 but can transmit the

energy peak around the period of minimum group

velocity (½ of T2 corresponding to the trough period T1

in Figs. 8b-8d) which constitutes an Airy Phase. Note

that through period T1 is nearly half of the peak period

T2 in the H/V spectral ratios presented in Figs. 6 and 8.

As a conclusion, the effect of multiple reflections of the

S-waves is composed mainly around the predominant

period T2 and the period of maximum energy

transmission of the Rayleigh waves is about a half T2 ≈

T1 [14].

The sharp peak (T2) and a sharp trough (T1) suggests

a high velocity contrast between the basement rock (VR)

and the velocity of the surface layers (VS) yielding

VR/VS ≥ 2.5 [10]. It is noted that the VR/VS ratio yields

2.3 between the limestone and the alluvium. Anomalous

H/V ratios above 100 are observed at some sites (Fig. 7),

the authors explain this phenomenon in Section 5.

A further examination of the H/V ratio for the

harbour area (port) is presented in Fig. 9. The H/V ratio

reflects three peaks at 3.0 s, 1.0 s and 0.4 s, which

presumably constitutes the fundamental mode and the

harmonics of the soil profile in the port. An important

characteristic of this quasi transfer function is that the

peak observed in the second period of vibration is

clearly caused by the trough in the vertical component

physically representing the change from retrograde

Fig. 7 Predominant period of soil based on horizontal to vertical spectral ratio (H/V) for the 218 points in Kingston Metropolitan Area.

Chalks Non-limestone Recrystallized Rubbly Yellow limestone


1311

Fig. 8 Rock site (a) and sediments sites (b-d) characterized by the effect of multiple reflections of the S-waves around the predominant period. Left: Fourier amplitude spectra for the horizontal and vertical components of microtremors. Right: H/V ratios, the horizontal motion is taken as the geometric mean of the N-S and E-W components.

(a) (b)

Fig. 9 A further examination of the H/V ratio for the harbour area (port): (a): Fourier amplitude spectra for the horizontal and vertical components of microtremors; (b) H/V ratios, the horizontal motion is taken as the geometric mean of the N-S and E-W components. The site is located in the harbor area with H/V ratios showing the fundamental mode and the harmonics.

0.1

1

10

0.2

0.3

0.5

2

3

5

H/V

ratio

0.1 10.2 0.5 2 5

Period (s)0.1 1

0.2 0.5 2 5

Period (s)

10

100

1000

Am

plitu

de (cm

/s2 *

s)

Graph 1N-S

E-W

Vertical2011/11/29 17:42:58

(a)

(b)

(c)

(d)

1,000

100

10


1312

Fig. 10 Fourier amplitude spectra for the horizontal and vertical components of microtremors at Portmore area (Left); H/V ratios, the horizontal motion is taken as the geometric mean of the N-S and E-W components (Right).

to prograde particle motion at the surface, in other

words, the ellipticity of the fundamental modes of

Rayleigh waves explain such peak at the second mode

of vibration, but is clearly not related with the resonant

S-wave fundamental period in the soil profile. This

feature is also observed within the municipality of

Portmore (Figs. 10a-10c) with the peaks in the period

range of 0.3 s to 1.0 s caused by the trough in the

vertical component, however, the shapes of the

absolute spectra and the H/V ratios yield different

features for the wave propagation in comparison with

the Liguanea Plain, the harbour area and Port Royal. It

is noticed that the Portmore area was part of the

flood-plain of the slow-moving Rio Cobre with the

result of a deposition of great thickness of fine grained

materials and with intercalations of sand deposits [15].

As a consequence of such intercalation of materials, the

authors can suggest that the peak observed might

correspond to the second mode of vibration

constituting the predominant period in this case [16].

0.1

1

10

H/V

Ratio

0.1

1

10

H/V

Rat

io

0.1 10.2 0.5 2 5

Period (s)

0.1

1

10

H/V

Ratio

0.1

1

10

H/V

Ratio

1

10

100

Am

plit

ude

(cm

/s2 *

s)

Graph 1N-S

E-W

Vertical

1

10

100

Am

plit

ude

(cm

/s2 *

s)

1

10

100

Am

plit

ude

(cm

/s2 *

s)

0.1 10.2 0.5 2 5

Period (s)

1

10

100

Am

plit

ude

(cm

/s2

*s)

(a)

(b)

(c)

(d)

2011/11/23 16:41:28

2011/11/23 12:55:02

2011/11/23 18:55:18

2012/06/24 18:56:14

Maximum

Minimum

Mean

(a)

(b)

(c)

(d)


1313

A flat H/V ratio of 1.0 is observed at the foot of the

limestone Port Henderson Hills near the Green Bay

(Fig. 10d) and ratio of 1.0 is observed in the shore of

the city for all frequencies of motion. A period of 1.0 s

is observed in the shore of the city.

Stiff soils or rock site conditions are generally found

on the hills surrounding KMA in the limestone hilly

areas, yielding an H/V ratio ≈ 1.0 for periods between

0.1 s and 2.0 s (Fig. 8a), however, the authors observed

soil sediments at some places in Stony Hill at the

northern of KMA yielding fundamental periods of 1.2 s.

The authors also found visible outcrop-rock conditions

toward to the north of KMA at the district of

Roehampton and surrounding areas (i.e., Constant

Springs and Arlene Gardens); these geological

conditions were confirmed with the microtremor

recordings.

At the north and east of Mona Reservoir, the authors

found the most irregular pattern for the period of

vibration between 0.6 s and 1.0 s, there is no clear

indication of a regular soil structure in this area, an

intercalation of coarse gravels and sands are reported

for this region [5].

The authors developed an isoperiod map for KMA

employing the 218 microtremors points (Fig. 7) and

interpolating the period values to a grid of 15 m × 15 m

via application of the minimum curvature method

(Fig. 11). This map shows similar patterns for the work

of Wald and Allen [17], yielding average shear wave

velocities in the first 30 m based on topographic slopes

at KMA. In a similar way, the authors developed a 3-D

model sediment depth for KMA derived by inverting

the depth H of Eq. (4) setting an average shear wave

velocity of 410 m/s and using the predominant periods

obtained by each H/V ratio of microtremors (Fig. 12).

The thickness distribution in the city appears to

correlate well with the MM (modified Mercalli)

intensity distribution observed for the earthquake of

January 13, 1993, M 5.5 and with shallow depth of 15

km located in the Blue Mountains [6].

Despite the epicenter was located to the north-east at

a distance of about 15 km from central Kingston, high

intensities of VIII MM were reported in the waterfront

where the thickest sediments are located according to

our model. Another earthquakes located 200 km away

from KMA in the Oriente Fault Zone at the South Cuba

has triggered intensities of IV MM in the Liguanea

Plain.

4.2 Comparison of Earthquake Motion Data and

Microtremors

The authors tried to elucidate the level of

amplification in the KMA employing earthquake data

and comparing them with microtremors, employing the

H/V ratio and an amplification factor developed by

dividing the actual ground motion by the motion

estimated at rock conditions using the ω2 model.

Brune [18] proposed a simple model to explain the

earthquake source in the frequency domain. He

considered a simple circular fault of radius r that

ruptures over its whole area at the same time [19]. The

method relates the spectrum of the shear radiation to

the stress released across the fault surface. The high

frequency level of the source spectrum is controlled by

the stress parameter (stress drop) and the low frequency

level proportional to the seismic moment, then the

observed spectra in this model depend on the

moment magnitude and the stress drop [20]. The

salient characteristics of the displacement

spectrum in the low frequency level are given by

Haskell [21]:

RRv

M

s

oo 34 (7)

where, Mo is the seismic moment in dyne-cm, R is the

radiation pattern coefficient (0.55 for average radiation

pattern of the double-couple radiation), is the density,

vS is the crust shear wave velocity (km/s) and R is the

hypocentral distance. At higher frequencies longer than

the corner frequency fc in the spectrum amplitudes falls

as f2 or ω2, where, ω (omega) denotes the circular

frequency (ω = 2πf). The corner frequency can be

found by:


1314

3/1

6109.4

oSc M

vf (8)

where, is the stress drop in bars. Then displacement

spectrum at a distance R is:

23 /1

1*

4)(

cs

o

ffR

Rv

MfD

(9)

McGuire and Hanks [22] suggested incorporating

the quality factor QS(f), to account the free-surface

effect (using a factor of F = 2) and the vectorial

partitioning of energy into two components of equal

amplitude (factor of V = 0.71). Also, they suggested

that the Fourier amplitude spectrum of acceleration can

be obtained by multiplying the displacement spectrum

by (2πf)2. Then, in a compact form, the Brune ω2 model

acceleration spectrum near the source for horizontal

component is Ref. [23]:

/ ( )2

2

1( ) (2 ) *

1 /

S SfR Q f v

oc

eAc f f CM F

Rf f

(10) where,

34 s

R VC

v

(11)

The stress drop and the seismic moment are used to

define the source spectrum, which is obtained in Eq.

(10) using the expression inside the brackets multiplied

by (2f)2 or prescribing R = 1.0. The authors should

remember that this constitutes an “apparent source

spectra” since it refers to the fact that these

representations are what the authors deduce from

far-field observations [24].

To obtain the seismic moment Mo (dyne-cm), we use

the moment magnitude MW and using the formula [25]

as follows:

7.10log3

2 oW MM (12)

The authors calculated the amplification factors

from the earthquake strong motion recordings

dividing the observed Fourier amplitude spectra by

the corresponding theoretical spectra employing

Eq. (10) setting 100 bars of stress drop, the QS(f) from

Fig. 11 Isoperiod map for Kingston Metropolitan Area, the units for the period are in s.

760000 765000 770000 775000 780000

Longitude (m)

645000

650000

655000

660000

Lat

itude

(m

)

0

0.2

0.6

1

1.5

2.5

3.8

Long Mountain

Hunts Bay

Caribbean Sea

Stony Hill

Henderson Hills

Port

660,000

655,000

650,000

645,000

0760,000 765,000 770,000 775,000 780,000


1315

Fig. 12 A 3-D sediments depth model for Kingston Metropolitan Area based on the period of the soil deposits and an average shear wave velocity of 410 m/s, the units of depth are in m.

McNamara et al. [26], vS = 3.8 km/s at the

correspondent distance R from the earthquake and

compare with both, the H/V ratio derived from

microtremors and the strong motion records; although

originally proposed to analyze microtremor data,

Lermo and Chávez-García [27] applied the H/V ratio

technique to earthquake ground motions recorded on

soft sediments in Mexico City, and obtained a good

coincidence with microtremor-based predominant

periods.

Figs. 13 and 14 illustrate the amplification spectra

resulting from the application of this procedure for an

earthquake event on 2011/05/06 09:29:22 UTC and

Mw 4.7 with an epicenter north-east of Kingston

(18.087 N, 76.652 W) and a shallow depth of 5 km. For

the station at the Toll Office in Portmore (SMS1), it is

clear that a very good match is observed for the

predominant peak for H/V of microtremors at 2.0 s and

the amplification factors derived from the ω2 model.

Similar characteristics are observed for the strong

motion at the station SMS2 on Portmore Bridge for the

same earthquake at the period of 2.5 s, the sharp peak at

0.65 s derived from the ω2 model and the H/V could be

attributed to the structural response being the

instrument located on one of the pillar footings of the

bridge. The authors performed the microtermor

measurement about 25 m away from this station due to

the immediate inaccessibility, being the footing of the

bridge surrounded by water. For both stations, the H/V

obtained by the earthquake recording present peaks in

longer periods, but not so well defined as the ones

obtained by microtermor recordings and the ω2 model.

The authors attribute these differences to the fact that

the vertical component comprised of body waves

undergoes no amplification for microtremors as stated

by Nakamura [3], while significant amplification can

take place in the vertical component during

earthquakes with earthquake epicenters located near

the station.

Konno and Ohmachi [10] suggested a simple formula

-380

-360

-340

-320

-300

-280

-260

-240

-220

-200

-180

-160

-140

-120

-100

-80

-60

-40

-20Stony Hill

645,000

660,000

650,000

655,000

760,000

765,000

775,000

770,000

780,000


1316

0.1 1Period (s)

0.1

1

10

Am

plif

ica

tion

Mean H/V of Microtremors

Max. and Min. H/V of Microtremors

Derived from Omega square model

H/V of earthquake data

Fig. 13 Comparison of transfer functions of microtremors and strong motion data for the Toll Office at Portmore (SMS1 in

Fig. 1).

0.1 1Period (s)

0.01

0.1

1

10

Am

plif

ica

tion

Mean H/V of Microtremors

Max. and Min. H/V of Microtremors

Derived from Omega square model

H/V of earthquake data

Fig. 14 Comparison of transfer functions of microtremors and strong motion data for the Bridge at Portmore (SMS2 in Fig. 1).


1317

(b)

Fig. 15 The harbour area, Port Royal and some areas at the Liguanea Plain have a high liquefaction potential: (a) Liquefaction index Kg based on microtremor measurements depicted in Figs. 5 and 6 and the polygon depicted in Fig. 1; (b) absolute Fourier spectrum and anomalous H/V spectral ratio in the harbor area.

for the amplification factor AS using H/V ratio of

microtremors, as follows:

(13)

where, RMB denotes the ratio at the peak. In this case,

we can attribute an amplification factor of 4 at 2.0 s for

SMS1, of 3.0 at 2.5 s for SMS2.

5. Preliminary Assessment of Liquefaction Potential

Nakamura [13] proposed a simple technique to

investigate the liquefaction potential based on

microtremor measurements, namely the vulnerability

index Kg for the surface ground, as follows:

-4 0 4 8 12Distance from Coast Line (km)

0.1

1

10

100

1000

10000

100000

1000000

Lique

fact

ion Ind

ex

(Kg)

Harbour Area

Port Royal

Liguanea Plain (Central West)

Mountain region

HIGH LIQUEFACTIONPOTENTIAL

LOW LIQUEFACTIONPOTENTIAL

10

100

20

30

50

200

300

H/V

ratio

0.1 10.2 0.5 2 5

Period (s)0.1 1

0.2 0.5 2 5

Period (s)

0.1

1

10

100

1000

Am

plit

ude

(cm

/s2 *

s)

Graph 1N-S

E-W

Vertical

Harbour Area

Maximum

Mean

Minimum

(a)

1,000,000

100,000

10,000

1,000

100

10

1

0.1

1,000

100

10

1

0.1


1318

(14)

where, Ag is the amplification factor referenced to the

engineering bedrock and Fg is the predominant

frequency of the soil profile (the inverse of the

fundamental period), both values can be taken from the

horizontal to vertical spectral ratio (H/V) of

microtremors, Ag is considered to be the H/V ratio at

the predominant frequency [10]. Values of Kg greater

than 20 are considered likely to liquefy.

The authors applied this method to the cross section

in Fig. 1 and H/V ratios presented in Fig. 6. The results

show that the harbour area, Port Royal and some areas

at the Liguanea Plain have a high liquefaction potential

(Fig. 15). It is worth mentioning that anomalous H/V

ratios above 100 for long period components

between 2-2.5 s are observed in the Liguanea and the

harbor area (Fig. 6, H/V ratios number 8, 7 and 11) due

to the very low amplitude and flat vertical absolute

Fourier spectra at these sites indicating a small

contribution of Rayleigh waves in the micromotion,

however, the authors observed the same fundamental

periods in the H/V ratio at other sites where significant

vertical amplitudes appear. Despite the difference in

the energy in vertical component of motion at different

sites, this phenomenon confirms that the quasi-transfer

function provides the fundamental period due to the

multiple refraction of SH waves in the surface ground

layers regardless of the influence of the degree of

Rayleigh waves. These characteristics were observed

also at some points in the waterfront area. As a further

evidence, Nakamura [14] suggested that in the case of a

low effect of Rayleigh waves, it is possible to estimate

both the fundamental periods and the second mode

caused by the multiply reflections of S-waves. These

characteristics were observed also at some points in the

waterfront area.

Performing continuous measurements at these sites

during one or two weeks will help to clarify the

distinction of long period microtremors or microseisms

due to ocean waves excitation and short period

microtermos (Kanai’s microtremors) due to human

activity, traffic, machinery, etc. [28].

The new Probabilistic Seismic Hazard Assessment

for Jamaica (see the article in the previous issues)

suggests a Peak Ground Acceleration for 475 and 2,475

years return period KMA of 0.25 g and 0.45 g

respectively at rock site conditions in KMA; the

saturated sediments on those areas can be classified

as sand/silty where the water table is located at the

surface. Liquefaction phenomena were observed

during the earthquake of 1907 at Port Royal (Fig. 16).

6. Microtremor Measurments on Buildings

We measured microtremors in the roof and in the

basement of four reinforced concrete buildings in

KMA in order to investigate the translational period of

vibration. The buildings for which we measured the

microtremors were: Ministry of Agriculture, Petroleum

Corporation of Jamaica, Ministry of Health and UDC

(urban development corporation) Office Centre

Building.

In order to eliminate the influence of the soil on the

roof measurements on the buildings, we divided them

by the micromotion recorded on the basement. Fig. 17

depicts the amplification functions of the buildings

showing clear predominant periods of vibration in the

transversal and longitudinal directions (Table 1). As a

Fig. 16 Liquefaction phenomena is still evident in the “Giddy House”, an ammunition store at Port Royal during the 1907 earthquake.


1319

0.1 10.2 0.3 0.5 2 3 5

Period (s)

0

10

20

30

40

Am

plif

icatio

n

Graph 1Transversal Direction

Longitudinal Direction

MINISTRY OF AGRICULTURE

0.1 10.2 0.3 0.5 2 3 5

Period (s)

0

20

40

60

80

Am

plif

icatio

n



PETROLEUM CORPORATION

0.1 10.2 0.3 0.5 2 3 5

Period (s)

0

5

10

15

20

25

Am

plifi

catio

n



MINISTRY OF HEALTH

0.1 10.2 0.3 0.5 2 3 5

Period (s)

0

5

10

15

20

Am

plif

icat

ion



UDC OFFICE CENTRE BUILDING

Fig. 17 Transfer function for reinforced concrete buildings based on microtremor measurements at the top and the bottom of the buildings.


1320

Table 1 Fundamental period of vibration and damping as percentage of the critical for buildings in Kingston Metropolitan Area for transversal and longitudinal directions.

Name of the building Fundamental period (s)

Transversal Longitudinal

Ministry of Agriculture 0.22 0.27 Petroleum Corporation of Jamaica

0.48 0.58

Ministry of Health 0.76 0.90

UDC Office Centre Building 0.73 0.79

preliminary observation, we note that the amplification

factors between the transversal and the longitudinal

directions differ twice and sometimes three times, the

lowest ones being always in the transversal directions

for which we observe the shortest fundamental period

of vibration, in other words, the microtremor

measurements reveal that the longitudinal direction of

the buildings is more flexible than the transversal

direction. An appropriate seismic coefficient might

have been taken into account during the phase

structural design in accordance with the architectural

building configuration and the stiffness/flexibility

observed in both directions.

7. Conclusions

At the Kingston Metropolitan Area, intensities of

MM VI or greater have been reported at a rate of 20

times per century, constituting the largest rate amongst

all Jamaican cities [29]. The authors clearly attribute

this fact to effects of the surface geology on the

earthquake ground motion in the city yielding average

depth of the sediments ranging from 200-300 m and

periods of about 2.0-3.0 s in the Liguanea basin.

Despite the fact that the predominant period of

vibration based on the H/V of microtremor

measurements coincide well with available geological

information, a more precise “level of amplification”

during future earthquakes at KMA is still a question to

solve. The authors have elucidated amplification

factors of about 3-4 for periods ranging 1.0-2.0 s

employing a very limited amount of earthquake ground

motion and microtremor data, but such few samples

lead to inconclusive statements for the whole city, even

more for short period components of ground motion

(0.1-1.0 s). In this regard, fundamental future work in

the area to perform microtremors array observation is

recommended in order to retrieve the shear wave

velocity profile information reaching the bedrock

based on conventional methods as the SPAC (spectral

auto correlation). Such arrays might be done in

different parts of the city in order to give proper

amplification factors that are dependent of frequency,

and to scale up the elastic design spectra developed in

the seismic hazard assessment for rock site conditions

presented in another article of the previous issues. The

first microzonation maps for KMA must be done for

both, the level of amplification with its correspondent

seismic loads and the liquefaction potential, which the

authors have demonstrated, represents a high hazard

especially in the Kingston harbour areas and Port Royal.

Kingston ranks as the 7th largest natural harbour in the

world and has a large concentration of infrastructure

through the KMA like oil refineries, power generation

plants and high rise buildings. The seismic hazard

paper presented in this previous issues clearly

demonstrated that a moderate size earthquake can

produce long term economic impact in the country due

to the substantial level of shaking, and the

amplification phenomena caused by the presence of

unconsolidated and saturated soils in the region.

The source of the microtremors can be elucidated if

continuous measurements are performed

simultaneously on rock and soil [28, 30] and compare

their amplitude with those of ocean wave heights or

changes in atmospheric pressure at the harbour. Their

survey indicates that long period microseisms are

present at rock site conditions observing a peak in the

long period components (above 4.0 s) in the “absolute”

Fourier spectrum that clearly does not correspond to

the presence of sediments at these sites (i.e., Figs. 8a

and 10d). Then the long period microtremors

(microseisms) and short period microtremors (Kanai’s


1321

microtremors) must be distinguished in future research

with continuous measurements at strategic points in the

city at rock site and deep soil conditions.

The deployment of a dense earthquake strong

motion network in the KMA is a must in order to

validate the results from the microtremors survey

together with systematic boreholes data that can

validate the microtremors array observation cited

above and the amplification factors that would arise

with the earthquake data. A future line of research in

the region is the acquisition of the dynamic properties

of medium and high rise buildings employing

microtremors, namely the fundamental translational

and rotational period of vibration and the damping ratio,

especially in zones where the resonant phenomena is

likely to occur.

Acknowledgments

Maps have been prepared using ESRI Arc Map 10.1

(Arc View) Geographic Information System and

SURFER Golden Software 8.

This study has been funded by the World Bank as a

part of the Risk Atlas Project for the Caribbean under

the supervision of the DRRC (Disaster Risk Reduction

Centre) at the University of the West Indies, Mona,

Jamaica.

The authors thank Paul Williams, Karleen Black,

Raymond Stewart, Stephanie Grizzle, Laurel Choy

(Earthquake Unit, Jamaica) and Omari Graham

(SRC/UWI, Trinidad) for assisting the authors in the

microtremors survey at Kingston Metropolitan Area.

The authors also thank the following institutions that

permitted them to make measurements at their

facilities/buildings:

(1) Kingston Container Terminal;

(2) The Port Authority of Jamaica;

(3) The Airport Authorities of Jamaica;

(4) Jamaica Defense Force;

(5) Urban Development Corporation;

(6) Ministry of Health and the Environment;

(7) Ministry of Agriculture;

(8) Petroleum Corporation of Jamaica.

References

[1] W. Salazar, V. Sardina, J. Cortina, A hybrid inversion technique for the evaluation of source, path and site effects employing S-wave spectra for subduction and upper-crustal earthquakes in El Salvador, Bull. Seismol. Soc. Am. 97 (2007) 208-221.

[2] W. Salazar, K. Seo, Earthquake disasters of January 13th and February 13th 2001, El Salvador, Seismological Research Letters 74 (4) (2003) 420-439.

[3] Y. Nakamura, A method for dynamic characteristics estimation of subsurface using microtremor on the ground surface, Quaterly Report of Railway Technical Research Institute 30 (1) (1989) 25-33.

[4] R. Ahmad, E. Robinson, Geological evolution of the Liguanea Plain—The landslide connection, in: Proceedings of the First Conference, Faculty of Natural Sciences, The University of the West Indies, Mona, May 1994, pp. 22-23.

[5] National Disaster Research, Inc., The Earthquake Unit, UWI, Mines and Geology Division, Jamaica, Kingston Metropolitan Area: Seismic Hazard Assessment Final report, U.S. Agency For International Development/Organization of American States, Caribbean Disaster Mitigation Project, Kingston Multi-Hazard Assessment, 1999, p. 82.

[6] M. Wiggins-Grandinson, T. Kebeasy, E. Husebye, Enhanced earthquake risk of Kingston due to wave field excitation in the Liguanea Basin, Jamaica, Caribbean Journal of Earth Science 37 (2003) 21-32.

[7] M.D. Wiggins-Grandison, Jamaican seismology and seismic hazard parameters, in: Jamaica Building Code Conference, Jamaica Pegasus Hotel, Kingston, Sep. 27-28, 2007.

[8] M. Nogoshi, T. Igarashi, On the amplitude characteristics of Microtremors (Part I), Jour. Seis. Soc. Jap. 23 (1970) 281-303.

[9] V. Rodríguez, S. Midorikawa, Applicability of the H/V

spectral ratio of microtremors in assessing site effects on

seismic motion, Earthquake Engineering and Structural

Dynamics 31 (2002) 261-279.

[10] K. Konno, T. Ohmachi, Ground-motion characteristics

estimated from spectral ratio between horizontal and

vertical components of microtremors, Bull. Seismol. Soc.

Am. 88 (1998) 228-241.

[11] R. Borchedt, Effects of local geology on ground motion in

San Francisco Bay, Bull. Seismol. Soc. Am. 60 (1970)

29-61.

[12] W. Aspinall, J. Shepherd, Modelling earthquake response

of the Liguanea—St. Catherine Plain of Jamaica in: 8th


1322

Caribbean Geological Conference, Curacao, 1977.

[13] Y. Nakamura, Seismic vulnerability indices for ground and structures using microtremors, in: World Conference on Railway Research, Florence, 1997.

[14] Y. Nakamura, On the H/V spectrum, in: The 14th World

Conference on Earthquake Engineering, Beijing, China,

Oct. 12-17, 2008.

[15] J. Turnosvsk, J. Shepherd, Microzoning for Earthquake

Effects in Kingston, Report No. 2, Mines and Geology

Division, Ministry of Mining and Natural Resources,

Seismic Research Unit, The University of the West Indies,

1976.

[16] W. Salazar, K. Seo, Spectral and amplification characteristics in San Salvador City (El Salvador) for upper-crustal and subduction earthquakes, in: 11th Japan Earthquake Engineering Symposium, Japan, 2002, pp. 329-334.

[17] J. Wald, T. Allen, Topographic slope as a proxy for

seismic site conditions and amplification, Bull. Seismol.

Soc. Am. 97 (5) (2007) 1379-1395.

[18] J. Brune, Tectonic stress and spectra of seismic shear waves from earthquakes, J. Geophys. Res. 75 (1970) 4997-5009.

[19] L. Reiter, Earthquake hazard analysis, issues and insights,

Surveys in Geophysics 13 (3) (1992) 297-298.

[20] G. Atkinson, Earthquake source spectra in eastern north

America, Bull. Seismol. Soc. Am. 83 (6) (1983)

1778-1798.

[21] N.A. Haskell, Total energy and energy spectral density of

elastic wave radiation from propagating faults, Bull.

Seismol. Soc. Am. 54 (1964) 1811-1841.

[22] R. McGuire, T. Hanks, RMS accelerations and spectral

amplitudes of strong ground motion during the San

Fernando, California Earthquake, Bull. Seismol. Soc. Am.

70 (5) (1980) 1907-1919.

[23] D. Boore, Stochastic simulation of high-frequency ground

motions based on seismological models of the radiated

spectra, Bull. Seismol. Soc. Am. 73 (6) (1983) 1865-1894.

[24] G. Atkinson, D. Boore, Evaluation of models for

earthquake source spectra in eastern north America, Bull.

Seismol. Soc. Am. 88 (4) (1998) 917-934.

[25] T. Hanks, H. Kanamori, A moment magnitude scale, J. Geophys. Res. 84 (1979) 2348-2350.

[26] D. McNamara, M. Meremonte, J.Z. Maharrey, S.L. Mildore, J.R. Altidore, D. Anglade, et al., Frequency-dependent seismic attenuation within the Hispaniola Island Region of the Caribbean Sea, Bull. Seismol. Soc. Am. 102 (2012) 773-782.

[27] J. Lermo, J. Chávez-García, Are microtremors useful in site response evaluation?, Bull. Seismol. Soc. Am. 84 (1994) 1350-1364.

[28] K. Seo, On the applicability of microtremors to engineering purposes: Preliminary report of the joint ESG research on microtremors after the 1993 Kushiro-oki (Hokkaido, Japan) Earthquake, in: 10th European Conference on Earthquake Engineering, Rotterdam, 1995.

[29] J. Shepard, W. Aspinall, Seismicity and seismic intensities in Jamaica, West Indies: A problem in risk assessment, Earthquake Engineering and Structural Dynamics 8 (1980) 315-335.

[30] K. Seo, JICA Research and Development Program on Earthquake Disaster Prevention, The Japan Building Disaster Prevention Association, JICA (Japan International Cooperation Agency), 1997.


The Idea of “Architecture Stage”: A Non-material

Architecture Theory

Yuke Ardhiati1, 2

1. Department of Fine Art and Design, Trisakti University, Jakarta 11440, Indonesia

2. Department of Architecture, Tarumanagara University, Jakarta 11440, Indonesia

Abstract: The purpose of this study is to find “the new theory” in the process of having quality “form” in architecture field which is usually visualized by the ruler through his ideology of his architectural work which is created by his architects. The study is about an urban design in architectural field related with space-power-knowledge. To reveal the meaning of the architecture objects is need to analyze the architectural object “form” as the culture-material, and to reveal the meaning of the objects through the hidden things related to the presence of the metaphysical data. To find “the new theory” used “grounded theory research”, the method is part of qualitative research which refers to Glaser and Strauss. The achievement study is finding the idea of “architecture stage” of the ruler, represented by Soekarno as the first Indonesian President. Through visual observation and spatial experiences in his several architectural works concerning the “Project’s Lighthouse” as his architectural work in Jakarta in the 1960s the idea of connectedness was found. He composes his architecture’s work by inserted the “architecture drama analogy” as metaphor for representing himself and his ideologist by exploring the Javanese Ancient’s as the basic design in the modern architecture at that time the east meet west. Key words: “Architecture stage”, grounded theory, khora, the ruler.

1. Introduction

The ideologist is usually visualized by the ruler

through his architectural work which is created by his

architects. The same phenomena of the ideas of

“architecture stage” abroad were revealed in the

architectural legacies of Adolf Hitler in Germany,

Joseph Stalin in the Soviet Union, Kubitchek in Brazil,

Mao Tze Dong in the People’s Republic of China, and

Nehru in India, also in Indonesia. However, there are

different types in Indonesia. Soekarno’s architecture

tacitly expressed his architectural knowledge in the

manner of “eastern meets western”, resulting in a

combination of differences between them. Soekarno

has given “color” as sense of presence in the ideas of

the “architecture stage Soekarnoestic” by combining

the charm of the Indonesian culture by exploring

Ancient Javanese form, Soekarno distinguished his

Corresponding author: Yuke Ardhiati, Dr., research fields:

architecture work, building conservation, theory and creative design for architecture and design. E-mail: [email protected].

architectural style based on Ancient Javanese culture

as the basic design to modern architecture. This was

done at a time when Hitler was composing his

architectural style which is almost similar style when

Stalin was composing the Stalinist Gothic. It also

different when Kubitcheck was designing the capital

city of Brazilia, when Nehru was composing

Chandigarh by Corbusier, and when Shanghai, China

was declared as the “Paris of the East” by local

architects. The finding ideas of “architecture stage” in

Indonesia was driven by desire, intervention and a

sense of art of Soekarno’s concept by exploring the

Javanese Ancient’s as the basic design in the modern

architecture.

2. Method

The paper is a part of architecture dissertation

investigation to express the civilization created by the

ruler represented by Soekarno, the first Indonesian

President. The study based on the archival data is a

part of la longue durée historical by Braudel, 1958 [1],

DAVID PUBLISHING

D

The Idea of “Architecture Stage”: A Non-material Architecture Theory

1324

it is architectural field related space-power-knowledge,

to find “the new theory” used “grounded theory”. This

method is also part of qualitative research referring to

Glaser and Strauss. The achievement study is to find

the idea of Soekarno as the ruler, when he creates the

space, through visual observation and spatial

experiences in his architectural works of the “Project’s

Lighthouse” in Jakarta in the 1960s. The data are

collected and named as coding, data analysis and

memoing—the final step to develop a new theory [2].

The research objectives in architecture field are

needed into three methods: (1) visual investigation; (2)

phenomenology’s investigation; (3) to reveal the

hidden meaning through the data metaphysical.

3. Results

After investigated in the several Soekarno’s work in

the “Project’s Lighthouse” in Jakarta in the 1960s, e.g.,

(1) The Jakarta City Planning; (2) the Gedung Pola; (3)

the Main Stadium of Gelora Bung Karno; (4) the

Hotel Indonesia; (5) the Istiqlal Mosque; (6) the

National Monument; (7) the Wisma Nusantara; (8) the

Sarinah Department Store; (9) the Planetarium; (10)

the Conefo’s Venue Building, a number of the city

scale sclupture’s was found [3]:

First, Soekarno’s works were inserting his

ideologist as his architectural communication when he

was creating the space of the “Lighthouse Project” in

order to establishment his power. His works reflect

the idea of “architecture stage” toward the

architectural form which is similar to characteristic of

khora [3]. Khora or Chora is a Greek term to express a

“concept of space” designated by Plato in Timaeus

[3-5]; Secondly, the “Lighthouse Project” looks like

“the abstract space” referring to Lefebvre, its role to

strengthen the social homogeneity through the

architecture work with characterized: spectacularly,

geometrically and phallic, was shown to the tenth of

the architecture works to beautification of Jakarta

Capitol City. The heritage buildings are contained

with a monad which is the immortality “immaterial

principle of life”. It is from the Old Javanese of

Indonesian ancient as the basic idea to create the

modern architecture.

3.1 The Jakarta City Planning

The Hotel Indonesia built as the pilot tourism and

as the Indonesian’s Face during the Jakarta City

Planning projects. Soekarno emphasized the

culturization to dreams Jakarta City which is

equivalent to the International city: Jakarta is as a

beacon that leads directly to participate pushing

development projects! The main idea of the Jakarta

City Planning are composed the eight lines of

Kebayoran Baru-Thamrin road inspired by the

Brazilia City Plan. The Jembatan Semanggi or

Semanggi Brigde is a clover bridge devided the four

directions of the Jakarta. The corridors of

Kebayoran—Thamrin looks like a “stage” resembled

a big catwalk on architectural work. Fig. 1 shows the

location of the “Project’s Lighthouse” in Jakarta in the

1960s in the main corridor of Jakarta.

3.2 The “Gedung Pola” Building

The Gedung Pola building is located in the heritage

site of Rumah Proklamasi—the House of

Proclamation on Jl. Pegangsaan Timur 56 Jakarta. In

this place, Soekarno read the Declaration of

Independence of Indonesia on August 17, 1945. Now,

the heritage is already ruins of buried foundation and

Fig. 1 The location of the “Project’s Lighthouse” in Jakarta in the 1960s in the main corridor of Jakarta.


1325

replaced by a big statue as the landmark of Soekarno’s

position when his reading the text of proclamation.

The open space building to facilitate the permanent

exhibition for the development project of Semesta

Berentjana Project years 1961-1969 is designed by

Silaban. Fig. 2 shows the “Gedung Pola” building

proposed by Silaban.

3.3 The Main Stadium Gelora Bung Karno

Soekarno’s desire is as the host of the Asian Games

IV on 1962 and must prepare the international venue

standard with capacity around 110,000 people by steel

structure change from concretes name: Temu Gelang

structure of Soekarno’s idea as the structure is

designed to follow the athletic activities pattern to

track continuously by the oval geometric shape.

Soekarno also put the ornaments of a realist sculpture

of mythical puppet Sri Rama to make it still be an

archery as the symbol of precision, agility, honesty.

The Gelora Bung Karno resembles a “architecture

stage” of Indonesia of Soekarno’s politician will. The

Main Stadium Gelora Bung Karno Gedung Pola

building is proposed by Russian architect (Fig. 3).

3.4 The Hotel Indonesia Building

In the front of hotel, it is located of statues and a

pool covered with a red lotus pond named Henk

Ngantung Fountain, and the welcoming to the young

men and women statue carrying a bouquette of

flowers, known as the Welcoming Statue as Edhi

Soenarso’s work to visualize Soekarno’s idea to give

the friendliness impression of Indonesian to the

foreign guests. Soekarno asked Abel and Windy

Sorenson, a couple architect to express his desire, and

adopted all of the name of the islands and the dance’s

name in Indonesia as the room’s name. Soekarno

ordered a variety of Indonesian artists to beautify the

building façade. A long andesite rock is created by

Harijadi entitling “The party in Bali” opposite the

statue of Goddess Sri created by Trubus. Under the

Ramayana’s big dome, it is found the reliefs color

“the Indonesian Women in Floating in Space” created

by Soerono. Behind the interior of the walls of dome,

it is filled the mosaic-art created by Darta’s name “A

Dance of Indonesia”. There are also found the realist

painting of Indonesia, Lie Man Fong in “the Indonesia

Flora and Fauna”. The diversities artworks displayed

at the Hotel Indonesia resembles the “Stage of

Indonesian Fine Art”. Fig. 4 shows Hotel Indonesia

building proposed by Abel Sorenson.

3.5 The Istiqlal Mosque

The Istiqlal Mosque is the largest mosque in

Indonesia and it is the Soekarno’s idea in 17 years

before the first pole in 1961, built as the victory symbol

Fig. 2 The “Gedung Pola” building.

Fig. 3 The main stadium Gelora Bung Karno.

Fig. 4 Hotel Indonesia building proposed by Abel Sorenson.


1326

of the Indonesian independence. The visual images of

mosque are dominated by the prime marble and

stained less steel, reinforced concrete structure with

the square pillars rhythmically across the facades. The

building with the giant dome is as a marker of the

grandeur to the Moslem’s with a tall minarets in the

corner’s building and as a symbol of the immaterial at

least for 1,000 years.

The Istiqlal Mosque designed to express the

modern architecture style with the solid structure and

rely on the natural ventilation. Fig. 5 shows the

Istiqlal Mosque building proposed by Silaban.

3.6 The National Monument

The National Monument or Tugu Nasional is

located in the center of the Medan Merdeka square.

Yet, it is known as the Champ de Mars or

Koniengsplain. It was built to express the “new soul

of Indonesian” as the dynamic nation in the modern

age. The monument is designed by National

Competition and held in twice, in 1955 and 1960, and

the both competitions have not been found the

ultimate winner, because its Soekarno is ordered to

Silaban and Soedarsono to develop the idea from the

first and second contest participants as a Final Design

Project. Finally, the Soedarsono’s design is accepted

by Soekarno. He design a pair of the giant cup and

phallic as the monument’s form and as the ancient

artifact symbol of Indonesia: lumpang and alu.. Refers

to Lobell’s theory of Spatial Archetype, the

monument shows the Radiant Axes civilization as

Soekarno’s unconscious as ruler. He reflected “the

world of emperor” linked with civilization, space and

psyche. Fig. 6 shows the national monument.

3.7 The Wisma Nusantara Building

The Wisma Nusantara is 29 levels high building to

facilitate the economic relations, trade and

international tourism in Jakarta. The building is

designed by Ciputra, which is as the first skyscraper in

Indonesia role and as the building Trade and Travel

Centre. The presence of the Wisma Nusantara

provided the quality space at the Hotel Indonesia

which resembles the Modern Architecture’s style, and

it is funded by the Japanese government. At that time

the first skyscraper in Jakarta is also projected as the

tallest building in Asia. Fig. 7 shows Wisma

Nusantara Building.

3.8 The Sarinah Department Store

The Sarinah Department Store now has undergone

changed all of the facades. Sarinah building is Soekarno’s

Fig. 5 The Istiqlal Mosque building proposed by Silaban.

Fig. 6 The national monument proposed by Soekarno himself visualized by Soedarsono.

Fig. 7 The Wisma Nusantara Building proposed by Ciputra.


1327

idea triggered the establishment of economic growth

as shopping, exhibitions, and office building also has

an important meaning as the price stabilizer. The

building is calculated by Roosseno’s engineer,

covered by ceramic materials, and floored by marble

and framing door and windows by aluminum. The

building is used the vertical transport escalators as the

first in Indonesia, reflected the new of life style during

in 1960s, and it is resembled the Indonesian

merchandise selection, ranging from food and

clothing as the modernities of Indonesia. Fig. 8 shows

the Sarinah Department Store Building.

Fig. 8 The Sarinah department store building.

Fig. 9 The Planetarium proposed by Ismail Sofyan and Ciputra.

Fig. 10 The Conefo’s Building proposed by Soejoedi.

3.9 The Planetarium Building

The planetarium designed as the largest in the

world, within 500 people seats as an educational

building to understand the aerospace science, to

eliminate the superstitions of Indonesians by activities

with observatory of the astronomy which is the

progressive symbol when it was still overwhelmed

with superstition regarding astrology. The building

shows the atmosphere of space to watch the stars and

the solar motion through a comfortable room. Fig. 9

shows the Planetarium proposed by Ismail Sofyan and

Ciputra.

3.10 The Conefo’s Political Venue Building

The Soekarno’s ideas to the “New World Order”

concept are visualized by the venue’s design to the

Conference Building of Conefo on August 1966 (but

nevertheless done). The Conefo’s competition is held

in November 1964, won by Soejoedi Wirjoatmodjo

and supported by Sutami. He present a full scale of

architecture model in the unique simetrical dome as

the aircraft wing and as a unique magnificent work.

Fig. 10 shows the Conefo’s Building proposed by

Soejoedi.

4. Conclusions

Soekarno’s architecture tacitly expressed his

architectural knowledge in the manner of “eastern

meets western” and he has given “color” as sense of

presence in the ideas of the “architecture stage” by

exploring Ancient Javanese form as the basic design

of Modern Architecture, and refers to Lobell’s theory,

the national monument’s symbol rays reveal the

Soekarno’s unconscious of the produce the

civilization and space linked with his psyche. The

hidden meaning of the Soekarno’s concepts of space

was found: The national monument not merely is a

physical immortality of architecture landmark, but also

reflects the “timeless of the immortal immateriality” by

Soekarno’s voice recording at the Amphitheater Room

and also reveal the ide “architecture stage”.


1328

References

[1] P. Burke, The French Historical Revolution: The Annales Scholl 1929-1989, Polity Press, Cambridge, 1990.

[2] B.G. Glaser, A.L. Strauss, The Discovery of Grounded Theory: Strategies for Qualitative Research, Adline Transaction, London, 2010.

[3] Y. Ardhiati, The stage of Indonesia: Khora charm works

of “Architect” Soekarno in the 1960s, Dissertation Thesis, Department of Architecture, Faculty of Engineering, University of Indonesia, 2013.

[4] A.G. Perez, S. Parcell, Chora 1, 2, 3: Intervals in the Philosophy of Architecture, Mc Gill Queen’s University Press, London, 1994.

[5] J. Derrida, On the Name, Stanford University Press, California, 1995.