TO EXAMINE THE POTENTIAL OF LAND USE UNDER FLYOVER IN THE ASPECT OF SAFETY

RPG 131-APPLIED QUANTITATIVE METHODS

LECTURER: DR. NORAZMAWATI MD. SANI @ ABD. RAHIM

SUBMISSION DATE: 27TH MARCH 2012

MEMBERS OF GROUP 18:

1. NG CHOO LIANG 1106752. NEO JUN CHEN 1106743. CH’NG SEE KEE 110608

TABLE OF CONTENT

1. TITTLE

2. ABSTRACT

3. INTRODUCTION

4. RESEARCH PROBLEMS

5. RESEARCH QUESTIONS

6. RESEARCH OBJECTIVES

7. RESEARCH FRAMEWORK

8. LITERATURE REVIEW

9. RESEARCH METHODOLOGY

10. ANALYSIS

11. RESULTS

12. DISCUSSION

13. CONCLUSION

14. REFERENCES

1.0Title

Development under Flyover in aspect of Safety

2.0 Abstract

Land use practices vary considerably across the country. Land use and land

management practices have a major impact on natural resources including water, soil,

nutrients, plants and animals. Land-use planning is the term used for a branch of public

policy encompassing various disciplines which seek to order and regulate land use in an

efficient an ethical way, thus preventing land-use conflicts. Land-use planning often

leads to land-use regulations, also known as zoning, but they are not one and the same.

Zoning regulates the types of activities that can be accommodated on a given piece of

land, the amount of space devoted to those activities and the ways that buildings may be

placed and shapes.

We also should consider the aspect of safety regardless of what type of building

that we are built. There are two slightly different meanings of safety. For example,

home safety may indicate a building’s ability to protect against external harm events

(such as whether, home invasion, etc), or may indicate that its internal installations

(such as appliances, stairs, etc) are safe for its inhabitants. Discussions of safety often

include mention of related term that is security. Security is the process or means,

physical or human, of delaying, preventing, and otherwise protecting against external or

internal, defects, dangers, loss, criminals, and other individuals or actions that threaten,

hinder or destroy an organization’s “ steady state,” and deprive it of its intended purpose

for being.

We may build highway under flyover. Traffic light is important to increase the

aspect of safety. Besides, developers can build a car park to utilise the land use under

flyover. Futsal Park is a good suggestion to build under the flyover. Informal markets

spring out selling chicken, fish, and fruit. There is still having many potential of land

use under flyover such as pocket parks, cycling path, night shelter and newspaper or

reading kiosks. In this report, we’ll discuss about what type of development can be built

under the flyover and also discuss the development in aspect of safety.

3.0 Introduction

Firstly, flyover refers to a high-level overpass that crosses over a highway

interchange or intersection. Land use is the human use of land. Land use involves the

management and modification of natural environment such as fields, pastures, and

settlements. Lands under flyover are usually left empty and we may build a car park on

the land, but we should consider it in aspect of safety. Therefore, the purpose of our

research is to examine the potential of land use under flyover in the aspect of safety.

Safety is the condition of being protected against physical, social, spiritual,

financial, political, emotional, occupational, psychological, educational or other types or

consequences of failure, damage, error, accidents, harm or any event which could be

consider non-desirable. There have several types of safety. Normative safety describes

products or designs that meet application design standards are met. Besides, substantive

or objective safety means that the real-world safety history is favourable, whether or not

standards are met. Lastly, perceived or subjective safety refers to the level of comfort of

users. For example, traffic signals are perceived as safe, yet under some circumstances,

they can increase traffic crashes at an intersection. So, we should taking safety

precaution before building a car park under flyover.

There are a lot of developments that we can do under the flyover if we didn’t

take safety into account as one of the suitability factor. But the reality is, whatever the

development projects it is going to be, safety always comes first. Hence, the potential of

land use under the flyover needs to be consider seriously in the aspect of safety as it

might involves up to hundreds of human’s life. Safety is not only covers the safety of

the people under the flyover, it also covers the people above the flyover and the people

around the flyover. Thus, safety is always a big issue when comes to a development

project and we need to find the potential of land use under the flyover from the main

aspect.

4.0 Research Problems

For the past 10 years, flyovers in Kuala Lumpur have obvious increment in

numbers which implies the areas occupied by the flyovers are also increasing. With the

rapidly growing development in the Capital city for the past 10 years, the land now

becomes scarce and limited. When the area occupied by infrastructure is increased then

the land now has become lesser and lesser. However, the land under the flyover is left

empty and undeveloped. This is because from the aspect of safety, nothing should be

build under the flyover because it might decrease the stability of the flyover itself.

Now, due to the scarcity of land in the Capital city, every inch of the city is

needed to be utilizing to the fullest. Then the first thing that comes into people’s mind is

to use the land beneath the flyover as it is empty and there are plenty of them almost

everywhere. Therefore, they need to re-consider the land use under flyover in the aspect

of safety again. Even though the land is empty but the potential of land use now is still

under planning phase only. This is because the flyover itself varies from its function and

there are some specific requirements for each function. For instances, the requirements

for flyover of public transport differs from the flyover of KTM or LRT trains.

Assuming the permission to build structures under the flyover is granted, and

then now we will have some lands to use for development. It will help to reduce the

price of the surrounding land by a little bit. On the other hand, it’ll also provide more

opportunity for jobs in the city. Imagine now you can build kiosks under the flyover and

you don’t need to purposely find an empty land for the kiosk along the roadside then

you’ll see how good it is. Land is one of the most important things in a city, the more it

is, the better it’ll be.

Therefore, in short, the potential of land use under the flyover is needed to be

considering seriously in the aspect of safety whether to the people beneath it or to the

flyover itself. In order to give the permission to build any structures under the flyover,

the engineering department of local authorities will need to evaluate the safety of the

structures and the effect of the structures to the flyover.

5.0 Research Questions

i. What kind of development that can be proposed under the flyover?

ii. What are the requirements or specifications of structures that are going to build

under the flyover?

iii. Which structures are suitable to be built under flyover without affecting the

stability of the flyover?

iv. Are the people under the flyover is safe from the traffics on the roads beside it?

v. Will the development under the flyover increase the traffics on the roads beside

it and contribute to the accident rate?

6.0 Research Objectives

The proposed study has been designed to attain following objectives:

To identify the potential of land use under the flyover.

To determine whether the development under flyover will affects the stability of

the flyover itself.

To determine whether the people under flyover will face any form of harm from

the surrounding.

To determine whether the development under flyover will affects the traffics

around it and lead to increase in accident rate.

7.0 Research Frameworks

To build a new and relevant research activity on examine the potential of land

use under flyover in aspect of safety, we need to have a good understanding of what we

wanted to know through this research and the appropriate research approaches in order

to produce a new knowledge.

A research framework defines the categories of independent variables and

dependent variables. Thus, in our research, our independent variable is to examine the

potential of land use under flyover whereas our dependent variable is the safety of the

development.

To examine the potential of land use under flyover is the independent variable as

we are free to choose what development we are going to discuss. Whereas the safety of

the development is the dependent variable as it is the primary interest to the researcher

(main issue). The dependent variable will respond to the independent variable in order

to get the results of this research.

In our research, the safety of the development is divided into 3 parts. The first

and the most important part is the effect of the development to the stability of the

flyover itself. For example, if the development requires a lot of drilling or piling, then

it’s not suitable to build under the flyover as it will weaken the strength of the

supporting posts throughout the whole construction period.

Then, the second part is the risk faced by the people if activities are carried out

under the flyover. Example, if the futsal court is being built under the flyover, is it safe

to be used? And will it be safe from the harm of the traffic beside the flyover? The last

part in the safety aspect is the effects on the traffic around the flyover after development

and will it increase the accident rate. For instances, after the development, will it

obstruct the traffic on the road beside it? Is there any increase in chance for accident to

be occur?

After all, the development should not be permitted if that will bring harm to the

flyover, to the people under the flyover or to the road user surrounding the flyover.

Safety is still the biggest concern among all the factors.

8.0 Literature Review

In most of the time, the land under flyover is considered dirty and dangerous.

There are not seen to be managed well by most people. But, this need not be so. We see

the space under the flyover as having wonderful potential. It is sheltered from the rain

and from the heat of the sun. Amazingly, it is also free of much of the politics, land

tenure disputes and real estate speculation that plague much of Bombay. The flyover

itself was proposed as necessary civic infrastructure. Why can’t this idea be extended

below as well?

In Mumbai, there is a flyover at Crawford Market area all the way to Byculla,

called JJ flyover. A team of developers, which are Stephanie Carlisle, Ankit Savla,

Sourav Biswas and PriyankaTalreja see the potential under the flyover and had planned

a project which to transform these small space under the flyover into places for play, for

shelter, for community building, for workship and for celebration, instead of parking

slots.

Figure 8.1: Proposal of developing the space under JJ flyover by a development team.

In Singapore, there is a futsal, or indoor soccer, under the Thomson Flyover. It is

a pilot project by the Singapore Land Authority to see how more of such land can be put

to better use. We should take some actions to think the way on how to fully utilize the

land without producing any negative impact to the public. For example, Singapore is a

land-scarce location, so it's good to increase the land utility under flyovers.

Figure 8.2: Futsal under Thomson Flyover, Singapore.

In Sydney Australia, parts of Darling Harbour have recreation and garden space

under flyovers. Specific uses include kiosks, public toilets, an interactive water feature,

a lawn area for kid's play. There may even be some retail space under the flyover on the

eastern side of the site.

Figure8.3: the freeway passes right over the commercial area of Darling Harbour.

Development means look into every details. We often see that there is lack of

proper management of the area under the flyovers. It is a bit messy and dirty, because

this issue is always ignored by most of the people. In fact, there is a very good potential

to develop the area under the flyover. A developer should fully utilize the land so that it

can bring benefits not only in the aspects of income, but also to the public, environment

and to the country.

9.0 Research Methodology

The research is carried out to examine the potential land use under flyover in

aspect of safety. By examining the various ways of land use under flyover in existing

cases, analysis on the safety and functional of the structures under the flyovers are

highlighted. At the end of the analysis, the criteria of a structure under the flyover in

safety aspect are listed out to be discussed and elaborated in the related sections. There

is a few of methodologies that we have used in the research. There are as follow:

a) Reference sources

The main sources of the research information are the Internet, books,

newspapers, magazines and other reading materials. We have found some information

about land use under flyovers in other countries through these resources. For an

example, we found that there is a futsal, or indoor soccer, under the Thomson Flyover in

Singapore. Fundamentally, this is a qualitative research whereby the project’s focus is

on the law, rules and regulations of land use under flyovers, ways to fully utilize the

empty space under the flyovers, and also the aspects of safety that the development of

free land under flyovers that can bring to public.

b) Observation

Besides, the research is also carried out through observations on the existing

cases in nearby area. Our group members have visited to Bayan Lepas Flyover to

identify the current ways of land use under the flyover at that particular area. It is

located in front of the Penang International Airport. The flyover allows traffic to bypass

the airport between the Bayan Lepas town and the free trade zone.

Figure 9.1: Picture shows the Bayan Lepas Flyover in Penang Island.

During observation, we found out that traffic congestion was a serious problem,

especially on Friday after office hours from the Bayan Baru flyover at Jalan Sultan

Azlan Shah to the traffic light junction at Jalan Sungai Nibong. The area under the

flyover is not fully utilized as well. There are, sometimes see some cars parking over

there, and some people selling things at there.

c) Conversational Interview

The qualitative research interview seeks to describe and the meanings of central

themes in the life world of the subjects. The main task in interviewing is to understand

the meaning of what the interviewees say. (Kvale, 1996). In conversational interview,

no predetermined questions are asked, in order to remain as open and adaptable as

possible to the interviewee’s nature and priorities; during the interview the interviewer

“goes with the flow”. Some examples of questions to be asked are:

What is the potential of land use under the flyovers in Malaysia?

How is the aspect of safety affect the design of structures under flyovers?

How to improve the safety of public by developing the infrastructure

under flyovers in Malaysia?

The research methods that are used enabled us to gather a vast amount of

information regarding the research problems. In order to provide the reader a clearer

view, all the inputs are carefully analyzed and systematically sorted.

However, the lack of quantitative data in the report is something we would like

to note about. An improvement to the research methods would be distribution of survey

forms and interview with the respondents so that first-hand statistical data would be

available to support the research findings.

 

10.0 Analysis

After we have done the research, we could list out the different ways of

developers on how they utilize the space under flyovers in other countries. Based on our

observation, we can said that most of the space under flyovers are used as car parks and

gardens, but there have some different cases, like in Singapore, there is a futsal, or

indoor soccer, under the Thomson Flyover. There are still many ways people fully

utilize the land under the flyovers. Based on the data gathered, lands under flyovers can

use as:

• Small gardens,

• Car parks,

• Futsal field,

• Advertisement boards,

• Emergency centres.

• Public toilets,

• Garbage dumpsites.

For every case, the pros are we can fully utilize the land in order to save the land space,

and of course for earning purposes in some cases. Build a small garden under flyovers

can beautifying the landscape, reducing the pollutant in that area and regulate the

temperature of the surrounding. Developing emergency centres and public toilet can

bring convenience to the public. By the way, any development under the flyover will

give more or less negative impact, especially in the aspect of safety.

Unlike the small area countries, like Singapore, Malaysia has a wider land to

develop futsal field compare to those countries that only have limited land, because

most of the lands were used for housing and commercial purposes to fulfil public need.

Build a futsal court under flyover is not safe for public, in more or less. Since the place

is just near the road, usually the frequency of vehicles passed by is high. Accidents may

occur anytime; hence the safety of the players may be affected. Besides, it is not

strategy enough to place a futsal field under the flyovers. The noise of vehicles, and the

pollutants that produced by those vehicles may affect the health of the players.

Imagine that the space under the flyover is used as a garbage dumpsite, there

will be rodents running around the area, this will increase the chances of accident in

road to occur. Pests like flies will reproduce rapidly and may affect the health of the

residents living nearby. Mosquitoes are likely to reproduce there as water may be

collected inside the garbage after rain. This will increase the risk of an outbreak of a

pandemic like malaria, a disease spread by the Aedes mosquitoes. In addition, the bad

smell of the garbage dumpsite may affect the daily life of public.

In aspect of safety, emergency centres and public toilets are not suitable to be

built under the flyovers as well. The live load and dead load above the structure of the

emergency centres and public toilets are too heavy, since many cars will pass by the

flyover. This can make the structure unbalance and tends to collapse. Moreover, the

siren from the emergency centres may disturb the residents near around.

Last but not least, having a small garden under flyovers will be the safest

method to utilize the land. By developing the small garden under the flyover, the safety

of public, pedestrians and driver will not be affected. It also will not cause the structure

to collapse. The most important thing is that the environment is conserved if the small

garden is built, since sustainable development is the main concern to the construction

field nowadays. It will be a place for passer-by to take a rest at the park, and the plants

at the parks will be provide the fresh air at the surrounding area while improving the

town’s landscape which can attract more tourists.

11.0 Results

Based on the conversational interview that our group members have done to the

public, the results of the public think the most suitable development under flyover in

aspect of safety are shown below:

52%

21%

5%

12% 3% 7%

The Potential of Land Use Under Flyover In Aspect of Safety

Small GardenCar parkFutsal fieldGarbage dumpsiteEmergency centreothers

In one hundred people that we had interviewed, more than half of them (fifty-

two out of one hundred people that interviewed) have proposed that develop a small

garden under the flyover is the most suitable way in the aspect of safety. On the other

hand, three out of one hundred respondents think that by developing an emergency

centre is the most suitable way in aspect of safety, which is the least amount of people

think in this way. This imply that most of them agree that by developing an emergency

centre is not safe to people.

Based on the results shown, developing small garden under the flyover is

seemed to be the most suitable solution in aspect of safety. It is not only environmental

friendly, but also brings lots of benefits to public.

12.0 Discussion

Malaysia has increasing numbers of flyover day by day; therefore the land use

beneath the flyover has gained more and more attraction day after day. The main

concern of this research is to evaluate the safety of the development under the flyover.

Currently, most of the flyovers are owned by the government or the PLUS Expressway

Berhad. If the flyover is the tracks of the trains, most probably it’ll be owned by

MyRapid or KTMB. The owner of the flyover owns the land too. Then proposal of

development projects not only needed to submit to the local authority but also the owner

of the flyover. This is because they need to evaluate whether this development will

affect the activities on the flyover and will the development affects the stability as well.

There are several types of development projects that are proposed under the

flyover. The examples are gardens or parks, futsal court, parking lots, garbage dumpsite,

emergency center and etc. All of these developments mentioned above is only consists

of mild construction process which doesn’t really involves much changes or vibration to

the land. Thus, most probably these developments will get their development permit as

it is not affecting the stability of the flyover and to the surrounding.

The most important thing in safety is the stability of the flyover. If the stability is

not conserved, then it’ll not only affect the user of the flyover, it’ll also endanger the

people under the flyover. Below are the explanations and ways to calculate the stability

of the flyover.

Internally stabilized soil retaining systems are also known as Reinforced earth

systems. They stabilize the soil mass by introducing tensile reinforcing elements such

as geosynthetic, steel straps, or soil nails into the backfill soil. It receives local support

(reinforcing) from the closest reinforcement as soon as any local yielding occurs; the

local yielding is confined by the nearby reinforcement before it develops into major

yielding of the entire backfill soil.

Figure 1. Reinforced Earth Retaining wall

1.1 Advantages (Sharma et al.,1996)

Flexibility – RE walls distribute loads over compressible soils, reducing the

need for deep foundations.

High load-carrying capability, both static and dynamic- Applied structural

loads are distributed through the compacted granular fill and earth pressure

loads are resisted by the gravity mass.

Ease and speed of installation - Prefabricated materials and granular soil

simplify construction.

Pleasing appearance - Panels may be given a variety of architectural

treatments

Economy -15-50% savings over cast-in-place concrete walls, depending on

wall height and loading conditions.

1.2 Brief description of Flyover project

As a part of traffic improvement scheme in Pune, flyover at Agriculture college road

has been planned to improve the capacity of a junction. The junction collects traffic

from Shivajinagar, F.C. Road and University Road. The project consists of a dual two

lane flyover from Agriculture College to University Circle for a length of

approximately 0.6 km. The elevated section of the flyover consists of prestressed

concrete deck of 16.4 m wide. The structure is divided into one unit of 400m consisting

of 6 spans of 35.5m and two ramps. At the starting phases of the work the detailed

drawings including L-section, typical cross-sections at various chainage, materials

properties were studied thoroughly and understood. The project involves the provisions

of earth fill of height ranging from 3.5 to 7m.

a)Soil properties:

o Retained backfill soils – γb = 20.00 kN/m3, φb =340

o Reinforced backfill – γr = 20.00 kN/m3, φr =340 (materials less than 15%

passing 75 micron, Cu=3.2)

o Foundation Soil – γf = 20.00 kN/m3, φf =300 (drained condition)

(Soil mix with gravelly silty sand up to a depth of 4.80m)

b) Geogrid: ACE geogrid are continuous grid structures with oval apertures.

c)Seismic data- Seismic zone III, max. Ground acceleration 0.16 [IS 1893 (Part

1):2002]

d) Traffic surcharge = 24.00 kN/m2

e)Parapet loading = 12.00 kN/m

f) Design Life = 100 years

2 Long Term Stability of RE wall

Stability is assured by providing a reinforced granular mass of sufficient dimensions

and structural capacity, bearing on adequate foundation material, having a durable

facing material, well-chosen drainage systems, and proper embedment of the toe of the

wall. Reinforced soil Earth structures are evaluated for external stability, internal

stability, wedge stability and seismic stability. Each type of stability will be discussed

separately. The static design is based upon the principles in BS8006: 1995.

2.1 External Stability

The Reinforced soil -geogrid volume is assumed to act as a rigid block, subject to the

conventional retaining wall failure mechanisms such as: Sliding, Overturning and

Bearing Capacity failure. The External stability comprises of evaluation of the base

width ‘B’ required for height ‘H’ of the wall. It is necessary that minimum factor of

safety of 2 against overturning, 1.5 against sliding and 2.5 for Bearing Capacity failure

(FHWA-NHI-00-043).

i) Factor of safety against overturning (FOS1) = MRO / MO

MRO = Resisting moment against overturning, MO = Overturning moment

ii) Factor of safety against sliding (FOS2) = ∑PR /

∑PD

= qult /

σV

Iii Factor of safety against Bearing capacity of

foundation soil. (FOS3)

qult = Ultimate bearing capacity of foundation soil,

σV = Maximum bearing pressure.

Table 1. Factor of safety with respect to wall height.

Sr.Height of

wall HTheoretical

widthFOS1 FOS2 FOS3

Adopted (width)‘B’(m)

No (m) ‘B’(m)

1 3.5 2.45 3.081 1.403 3.357 2.502 4.0 2.80 3.246 1.529 3.511 2.803 4.5 3.15 3.387 1.636 3.640 3.204 5.0 3.50 3.509 1.729 3.750 3.505 5.5 3.85 3.616 1.809 3.845 3.906 6.0 4.20 3.710 1.879 3.928 4.207 6.5 4.55 3.793 1.940 4.000 4.608 7.0 4.90 3.550 2.030 3.910 5.00

The practice is to provide minimum value of ‘B’ as 0.7 H but not less than 2.45m (BS8006: 1995).

2.2 Internal Stability

Internal stability design consists of the determination of Geogrid size, quantity, and

lengths. Internal stability analyses are: the Geogrid layers layout, tension failure and the

Pullout failure. There is two possible limiting or failure conditions for reinforced walls:

rupture and pullout of the Geogrid. The corresponding properties are the tensile strength

and its pullout resistance.

Potential failure plane

Active zone

T = Total tensile

force to be resisted

by Geogrid

Resisting zone

Figure 2. Adherence capacity of geogrid reinforcement

Calculations (FHWA-NHI-00-043):

i. Consider Geogrid layer vertical spacing (Vs) = 0.47m

ii. Tension calculation at each Geogrid reinforcement level T(Max) = σH x Vi

iii. Allowable strength (Tall) = [Ultimate strength (Tult) x RC / FS uncertain x

FSID x Creep reduction factor]

Where, FS uncertainties = 1.5, FSID = 1.1,

RC = the percent coverage ratio (100 % coverage is assumed for this case) So

RC = 1, Creep reduction factor = 3.10

iv. Pullout calculation at each layer Tmax ≤ (1/ FSPO) (tan φ

Ci) (γr) (di) (Le) (C) (Rc) (α) Where, FSPO = factor of

safety against pullout = 1.5,

Ci = interaction coefficient determined from pullout testing for a particular

reinforcement type. Ci = 0.8,

γr = unit weight of reinforced soil mass, di =

depth below top of wall. Le = length of

reinforcement in resistance zone. C = 2 for

Geogrids.

Rc =% coverage of Geogrid (may vary from 100% to 70%). Rc assumed to be

100% for this example,

α= scale effect correction factor (α = 1.0)

v. Length of Geogrid in active zone LA = (H – di) x tan (45o - φ / 2).

Table 2 Output for 7.04 m wall for type and length of geogrid at each layer.

Layer No

Depth (di) from Tmax

Type of ACE T(all) L(required)

L (provided)

Top (m) (kN/m) Geogrid (kN/m) LA + Le (m) (m)1 0.47 6.64 GG40-I 7.82 4.495 5.02 0.94 5.67 GG30-II 5.86 4.245 5.03 1.41 6.86 GG40-I 7.82 3.995 5.04 1.88 8.10 GG60-I 11.73 3.745 5.05 2.35 9.34 GG60-I 11.73 3.495 5.06 2.82 10.58 GG60-I 11.73 3.245 5.07 3.29 11.81 GG80-I 15.64 2.995 5.08 3.76 12.97 GG80-I 15.64 2.745 5.09 4.33 14.29 GG80-I 15.64 2.495 5.010 4.70 15.52 GG80-I 15.64 2.245 5.011 5.17 16.76 GG100-I 19.55 1.995 5.012 5.64 18.00 GG100-I 19.55 1.795 5.013 6.10 19.23 GG100-I 19.55 1.495 5.014 6.58 30.27 GG150-I 39.10 1.245 5.0

It is observed that total length of Geogrid required at each layer is less than length

required from external stability analysis. So length of Geogrid provided is equal to 5 m

at each layer.

2.3 Wedge Stability

It is essential to ensure safety of geogrid reinforced earth wall against failure over potential

sliding plane. Stability of any wedge is maintained when frictional forces acting on the

potential failure plane in connection with the tensile resistance or bond of the group of

reinforcing elements embedded in the fill, bed and the plane are able to resist the applied

force tending to cause the movement (Figure 3).

P = Frictional and cohesive forceN = Normal reaction q = Surcharge weightT = Total tensile force to be resisted by Geogrid

Figure 3. Forces acting on Potential failure planes

Calculations (BS8006: 1995):

i) Resolving the forces vertically. W T = N Sin β + P Cos β

ii) Resolving the forces horizontally. T + P Sin β - N Cos β – F3 =0

iii) Residual length (effective length) Lr = L – (H - di) Tan β

iv) Calculation of resisting force at each layer

a)Rf = Tall x Lr,

b)Rf = μ x Lr (γr x di + q) [Ref.B.S 8005: 1995 (Cl. 6.6.4.2.5)]

The lesser value for each layer should be used in the summation.

Based on the procedure listed under illustrative computation, a computer programme is

developed to calculate Rf for all reinforcement layers & min. value of each layer is consider

for summation. The output is obtained for 7.0 m height of wall.

26

Table 3. Output for wedge stability analysis

Sr. No.Depth of layer

(di) (M)Resisting Force (kN)

1 0.47 11.762 0.94 10.273 1.41 15.644 1.88 26.435 2.35 29.376 2.82 32.307 3.29 46.928 3.76 50.909 4.23 54.74

10 4.70 58.7211 5.17 78.2012 5.64 83.1813 6.10 88.0714 6.58 185.92

∑ Rf = 760.66 kN

FOS = ∑ Rr = 760.66 = 2.84 > 1.5 (Hence O.K)

T 267.63FOS against wedge stability for height 7m is greater than 1.5; hence structure is safe.

27

13.0 Conclusion

Land only covers 29.22 percent of the Earth surface which water covers the other

70.78 percent of the Earth's surface. The land is still depleting because of the rising of sea

level due to global warming. Therefore, we should make good use of the existing land. By

fully utilizing the land, we will be able to help in solving the land scarcity problem.

From the vast development in the infrastructure field, the land under the flyover has

now draws the attention of the developers. It is a waste of land if the space under the flyover

is left empty. However, there is a reason why this is happening. This is because from the

safety aspect, ‘nothing’ should be built under the flyover.

Things change with the situation, adaptability, that’s the basic rule of life. In a fully

developed city where there’s no more land to develop, the land under the flyover is as

precious as diamond in the developers’ eyes. Thus, the developers urge the local authorities

to re-consider of allowing development under the flyover. But there’re still specifications and

requirements that need to be follow by the developers and the Engineering department from

the local authority should decide whether the development is safe to be build from all aspect.

In conclusion, the final decision whether the development should be permitted or not

lies on the shoulder of the engineer from local authorities. The development under the flyover

should be seen as fulfilling one of the urban planning strategies in minimizing the wastage of

land. There are a lot of potential of land use under the flyover however to avoid any tragedy

from happening, safety awareness is very essential in the development.

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14.0 References

I. MDC Legal Advisers, National Land Code Act 56/196, MDC Publishers Printer Sdn.

Bhd., 2001

II. Offside Futsal Park opens under Thomson Flyover-Singapore

http://www.futsalplanet.com/news/news-01.asp?id=15963

III. Australian Freeways and Roads

http://www.skyscrapercity.com/showthread.php?t=434396&page=19

IV. Under the Flyover | URBZ

http://urbz.net/workshops/mashup/mumbai/under-the-flyover/

V. Space under Flyovers, Praja

http://praja.in/en/blog/varsh/2010/03/26/spaces-under-flyovers

VI. Cebu Daily News

http://cdn.ph/news_details.php?id=12602

VII. A community space under a traffic flyover is the latest hip hangout

http://uk.phaidon.com/edit/art/events/2011/july/19/a-community-space-under-a-

traffic-flyover-is-the-latest-hip-hangout/

VIII. The writers would like to thank Mr. Karamarakar, Mr. Konage of M/s Dar

Consultant Pune for providing us the detailed information of the flyover at

agriculture college road, Pune, India. The writers also would like to thank faculty

of Civil Engineering Department of COE, Pune and AISSMS College of

Engineering, Pune.

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