RAPID VISUAL SCREENING OF BUILDINGS

Chandan Ghosh, Ph.D., Dr. Engg.Professor & Head [GeoHazards Divn.]

National Institute of Disaster ManagementMinistry of Home Affairs, Govt. of India

2

RVS – what to screen?

Threats from potential hazards – say Fire, Earthquake….

What are the scenario in our cities?

3

RVS for Gangtok – how?

MMI City PopulationVI Gangtok 31kVI Shiliguri 516kVI Mangan 1kVI Naya Bazar 1kVI Namchi 1kVI Singtam 6k

NIDM visit 22-26 Sept 2011

VI MMI (Strong shaking) Felt by all, many frightened. Some heavy furniture moved; a few instances of fallen plaster. Damage slight.

VII MMI (Very strong shaking)Damage negligible in buildings of good design and construction; slight to moderate in well-built ordinary structures; considerable damage in poorly built or badly designed structures; some chimneys broken. VIII-MMI

VII-MMI –Delhi ‘s fate

SAFETY PERSPECTIVES OF BUILT-ENVIRONMENT - WHAT IT CARRIES FINALLY?

Hyogo Framework for Action 2005-15

Ensure that disaster risk reduction is a national and a local priority

Identify, assess and monitor disaster risks and enhance early warning

Use knowledge, innovation and education to build a culture of safety and resilience

Reduce the underlying risk factors.

Strengthen disaster preparedness for effective response at all levels.

Insured vs. Total Economic Loss in Major Natural Catastrophes

100%47%

40%

8%0.3% 2% 4% 5% 5% 6% 6% 7%

0%

20%

40%

60%

80%

100%

Bangladesh (Floods, 1

998)

India (Gujarat/B

huj, 2001)

El Salvador (S

an Salvador, 1

986)

Turkey (Izmit,

1999)

Mexico (Mexio City

, 1985)

Honduras (Mitc

h,1998)

Poland (Floods, 1997)

Columbia (Arm

enia, 1999

)

Indonesia (Floods, 1

996)

Puerto Rico (H

ugo, 1989)

USA (North

ridge, 1992)

France (Storm

Lothar, 1999)

Insured Uninsured

5,000

4,571

2,000 21,591

10,024

5,000

3,700

1,660

Source: Swiss Re CatNet database, AXCO database

136 2,000 36,406 4,535

Total Economic Loss (US$MM)

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What went wrong?

Before 26 Jan 2001

Rao Lakha Chatri, Bhuj

After 26 Jan 2001

12

Any documents/handbook for such buildings?

Who is engineer?

Courage and integrity Thrust for Knowledge Integrity Capacity for sound judgement Capacity for hard work Imagination Instinct for economy Aptitude for leadership Accuracy for thought for action

John SmeatonFather of Civil Engineering

( 1724 – 1792 )

Civil Engineers are self created set of Men, whose profession owes its origin not to power or influence ; but to the encouragement of a great & powerful nation.

We civil Ers/Ars can contributeSignificantly towards above cause

History of Civil Engg In the beginning, Civil Engineering included all engineers

that did not practice military engineering; said to have begun in 18th century France.

First “Civil Engineer” was an Englishman, John Smeaton in 1761.

Civil engineers have saved more lives than all the doctors in history — development of clean water and sanitation systems.

Henry H. White, first KY Civil Engineering Graduate from Bacon (Georgetown) College in 1840.

• Fall of 1886, “State College” (UK) established civil engineering

degree.

• John Wesley Gunn of Lexington received first Civil Engineering degree from A & M College (UK) in 1890.

Constructing earthquake resistant structures is the best opportunity to save lives of human beings – A second opportunity.

World Without Engineers ?

EARTHQUAKE EFFECTS TO UNDERSTAND

Golcuk Mosque( Istanbul ) Standing Tall amidst erased buildings ( 1999)…

Survival of the fittest

Totally collapsed & undamaged Builidings

Northridge CA 1964Kobe Japan 1995

TV Tower Ahmedabad Undamaged Transmission Tower near Epicentre

Principal Reasons of failures…

Principal reasons of failures during Earthquake

1. Quality of Concrete .

2. Construction on reclaimed soil .

3. Insufficient Depth of Foundation

4. Absence of Tie/Plinth Beams .

5.Absence of Beam at Sill level. .

6. Hollow Plinth or Soft Story. .

7. Stub/ Floating Columns

8. Odd shape of building.

9. Erroneous Structural Designs

10.Use of hand mixed concrete in columns

27

Eq. resistant construction – possible?

28

Context

Buildings performance in earthquake Construction monitoring and PEER

check Damage patterns and mitigations Economic feasibility of mitigation Health monitoring of buildings – RVS

for Delhi Post-EQ. health check Road Map

Bhuj-2001 …This building was reduced by one floor – reason? livable?

Stone wall, 10.23%

Conc. Wall, 2.63%

Mud wall, 29.63%

Metal sheets, 0.80%

Brick wall, 44.92%

Wood, 1.28%Bamboo,

10.51%

Category of building stocks in India - Census (2001)Total houses = 24.9 million

Lok Sabha starred Q. on 22nd Nov 2012

Whether our infrastructures are vulnerable to impending hazards

Economics of disaster – scientific or unscientific

Mitigation measures – economically viable or not

ANY ECONOMIC FEASIBILITY ASSESSMENT DONE SO FAR?

AS OF 2004 REPORT – WE LOSE 2% OF OUR GDP EVERY YEAR

Faulty construction – who shall stop such practices?

Urban health & safety

Vulnerability of buildings

Lalita park- after effect

Poor constructions - Shimla

What is RVS?Rapid Visual Screening (RVS) is a cheap

and fast procedure in assessing the safety of buildings and classifying them according to the risk that they pose in times of strong earthquakes.

Primarily (1)identify the primary structural lateral

load-resisting system, and (2) identify building attributes that modify

the seismic performance expected for this lateral load-resisting system along with non-structural components

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• Site specific concerns and other comments• Maintenance concerns and other comments• General environmental control – housekeeping

and other comments• Fire & Electrical Hazard Prevention and Safety

Concerns And Other Related Comments • General safety concerns and other commentsName and designation of the field

inspector/Engineer:_______________Signature:________

Experience of Inspector/engineer:Contact No.:

 Name and Designation of the Evaluator:________________ Signature:___________

Email: Contact No. ________________

Q1. Does the building have an open storey with just columns and no Unreinforced Masonry Infill walls, either at the ground level or at any intermediate storey level

Soft storey at the ground

X-bracing takes care of shear forces due to earthquakes

Crushed cars

49

Q2. Does the building have floating columns or floating structural walls (discontinued in the lower levels)

Q3. Are the columns having transverse reinforcement with 90o hook ends?

Q4. Does the building have slander columns and deep beams at any of the beam-column junctions?

Q7. Are adjoining buildings or adjoining parts of the same building separated by less than 2% of the height of the building?

Q12. Are the main load bearing columns oriented along the length of the building plan?

Pounding

57

Q17. Did the building suffer any significant damage in the past due to earthquake or other hazards?

On December 19, 2011, 8 people killed and 3 injured in a bridge collapse at Rangchang Khola, about 18 kms from Singtam towards Dikchu on the Singtam-Mangan highway. The incident took place when a 48-wheeler heavy trailer carrying transformer of Teesta Urja Project to its project site in North Sikkim was attempting to cross the bridge span.

59

Q18. Does the building possess any seismic retrofitting or strengthening measures?

60

Ludlo castle School –Delhi 2007

EQ. resistant measures

62

Q19. Does the building have basement with short openings/ventilations over ground?

opening at the basement above ground – good ventilation BUT

Q21. Are the load bearing columns continued from ground to top floors?

Building with NO columns at upper floors

66

Q22. Is there any alteration/modification done for extra room/wall cabinet any time in its lifetime?

67

Q24. Are the beam-column supports/junctions centrally positioned in all floors?

New constructions – no field check

Corner col. has diff. reibars, high tension wires too close

Construction flaws -

• Rise in population, robust democracy….• Increasing gap between have and have

nots….• Unplanned and ill-planned settlements• Settlement in and industrialization of

extremely exposed regions • Lack of enforcement mechanism….• Lack of policy implementation…• Political will and attitude….• Change in environmental conditions - Climate

Change

Reasons for globally increasing losses

due to natural disasters – general…

Haity EQ. 2010 – before and after [importance of open space]

RVS - Rapid Visual Screening (1) identify the primary structural lateral

load-resisting system, and (2) identify building attributes that modify

the seismic performance expected for this lateral load-resisting system.

(3) The screening is based on numerical seismic hazard and vulnerability score. The scores are based on the expected ground shaking levels in the region as well as the seismic design and construction practices for the city or region.

Rapid visual screening (RVS) Purpose of RVS is to classify “those acceptable

as to risk to life safety or those that may be seismically hazardous” (FEMA, 2002a).

RVS scores are a quantitative measure of the probability of collapse and collapse is the predominant determinant of life safety risk for buildings.

RVS scores are useful in the evaluation of life safety risk and in the prioritization of seismic retrofit programs for populations of buildings.

Levels of Analyses

1. Rapid visual screening (RVS) procedure requiring only visual evaluation and limited additional information (Level 1 procedure). This procedure is recommended for all buildings.

2. Simplified vulnerability assessment (SVA) procedure requiring limited engineering analysis based on information from visual observations and structural drawings or on-site measurements (Level 2 procedure). This procedure is recommended for all buildings with high concentration of people.

3. Detailed vulnerability assessment (DVA) procedure requiring detailed computer analysis, similar to or more complex than that required for design of a new building (Level 3 procedure). This procedure is recommended for all important and lifeline buildings.

Use of RVSTo identify if a particular building requires further

evaluation for assessment of its seismic vulnerability. 2. To rank a city’s or community’s (or organisation’s

seismic rehabilitation needs. 3. To design seismic risk management program for a

city or a community. 4. To plan post-earthquake building safety evaluation

efforts. 5. To develop building-specific seismic vulnerability

information for purposes such as regional rating, prioritisation for redevelopment etc.

6. To identify simplified retrofitting requirements for a particular building (to collapse prevention level) where further evaluations are not feasible.

7. To increase awareness among city residents regarding seismic vulnerability of buildings.

Seismic vulnerability classification

Building types (1) masonry buildings, (2) RCC buildings, (3) steel buildings, and (4) timber buildings.

Site class as per FEMA 154

Site class A - Hard rock with measured shear wave velocity greater than 5,000 ft/sec.

Site class B - Rock with shear wave velocity between 2,500 and 5,000 ft/sec

Site class C - Very dense soil or soft rock [velocity between 1,200 and 2,500 ft/sec]

Site class D - Stiff soil [velocity between 600 and 1,200 ft/sec]

Site class E - Soil profile with velocity less than 600 ft/sec

Site class F - Soils require site-specific evaluations [liquefiable, peats, high plasticity, or very thick soft/medium clays.

Building system performance Ductility. Strength and Stiffness. Bracing/Seismic Resistant Components. Braced frames . Moment resistant frames (generally of steel or

reinforced concrete) consist of beams connected to one or more columns to carry multi-dimensional earthquake forces.

Horizontal Diaphragms are floor and roof deck systems that carry forces across the building to shear walls, braced frames, and/or columns.

Shear walls are large structural walls placed in a building to carry forces from the roof and floor systems to the supporting foundation, and into the soils.

Cross walls are interior walls and partitions that are not necessarily continuous to the foundations, but which are attached securely to two floor diaphragms (the top side of a floor diaphragm to the underside of the floor above) and that are stiff and strong enough to resist the independent movement of the two connected diaphragms.

Connections. Damping. Weight Distribution.. Building Configuration. Foundation / Soil Characteristics. ground shaking

frequency played a significant role.  Sites with rock close to or at the surface will be less likely to amplify motion, and with such sites, generally, the farther from the source of an earthquake, the less severe the motion.

Resonance.   Redundancy. 

Building survey in East Delhi Lalita park building collapse – 71

died, 65 injured Judicial inquiry commission by Delhi

Govt. Forensic investigation – NIDM (Jan-

Apr 2011) Structural safety of all buildings in

east Delhi – NIDM (May 2011 to till date)

10000 building Survey in East Delhi

MCD engineers trained at NIDM Format devised – more than 250

parameters Survey conducted by MCD engineers at

64 wards simultaneously Mapping done for 2 wards – 221, 222 Software developed

RVS in East Delhi by NIDM

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RAPID VISUAL SURVEY OF BUILDINGS IN EAST DELHI

Building Identification

GENERAL INFORMATION Building Name:__________________________________________________________________ Ownership: Public _______ Private______________________ Owner’s Name: __________________________________________________________________ House Number _______ , Street/ Lane No _______ ____________________________________ Name of colony ______________________________, District ____________________________ Nearby Landmark ______________, Delhi/New Delhi ____________ PIN __________________ Name of Police Station____________ Name of nearest Fire Station____________________

Note: Take representative photo and measurements, draw sketches/locations of stair cases, drains, etc. showing good and bad aspects from the view point of earthquake safety and vulnerability.

1. Building type:

(a) Earthen building ___________________ (b) Stone in mud mortar _________________

(c) Stone in cement mortar _____________ (d) Brick masonry in mud mortar _________

(e)Brick masonry in cement mortar_______ (f) RCC Frame Building________________

(g) RCC Frame- shear wall Building ______ (h) Mixed Construction (specify):_________

2. Building area: (a) Approved___, (b) unauthorized regularized__, (c) unauthorized________

(d) Rural Village_,(e) Urban village_,(f) Resettlement colony____, (g) others (specify)______

3. Usage of the building: (a) Residential _____,(b) Commercial________,(c) Offices __________, (d) Public ________

(e) Storage ____,(f)Housing Society _____,(g) Hospital/Health centre __, (h) School ______

(i) Coaching Centre _ (j) Religious places ____,(k) Petrol pump __________, (l) Police station _ (m) Fire

station ____, (n) Shopping Mall ____, (o)Community Centre __________ (p) mixed use ___ (q)

Cinema Hall____, (r) Others (specify) ____

4. Number of occupants/users (approximately):______________________________________

5. Age of construction : (a) ongoing construction _____________________________________

(b) Constructed < 5 yrs ___, 5-10yrs ___, 10-20 yrs ___, >20 yrs ___ Others (Specify) ______

Ward Colony Code Block House Number

640

256320

548608612658

971863925

1037925

804717

276174

Total survey in North and South zone

Till A

pril 3

0th

May 3r

d

May 5t

h

May 7t

h

May10

th

May 12

th

May 14

th

May 18

th0

100020003000400050006000

Survey in North and South zone

Residential 79%

Commercial11%

Offices0%

Public0%

Storage1%

Housing Society1%

Hospital /Health Centre

0%

School0%

Coaching Centre0%

Religious Places0%

Police Station0%

Fire Station0%

Community Centre

0%

Mixed Use8%

Other (Specify)0%

Buildings surveyed by MCD ( 10334 no.)

Special surveyAppartment

4%Com-

mercial13% Com-

munity centre

1%Edu-cation

al6%Fire

Station1%

Hospital5%

Insti-tu-

tional2%Mixed Use

9%Public

5%Petrol Pump2%

Police Station1%

Religious2%

Residential34%

School4%

Tank0%Tower

1%

Under Construction9%

Special survey - 300 buildings

0

1000000

2000000

3000000

Building Area In East Delhi

Build

ing

area

(m

2)

246-Ashok Nagar

272-Sabhapur

265-Shiv Vihar Phase-1&phase-2

214-Vasundhra Enclave

240-Old Seemapuri

227-Ghazipur Village

272-Sonia Vihar

266-Babu Nagar & Prem Vihar

272-West Karawal Nagar

272-Rajiv nagar

270-Khajoori Khas Extension

268-Brij Puri

262-Gokalpuri

225-Karkardooma,Rishabh Vihar,Surajmal Vihar, Yojana Vihar,Savita Vihar

225-Anand Vihar Metro ,Bus ,Railway

234-236-Kailash Nagar, Chand Mohalla

0.00E+005.00E+05

1.00E+06

Road Area In East Delhi

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Professionally where we are now?

Are the BIS codes and NBC enough? EQ. resistant technology well established –

implementation & enforcement? Seismic microzonation – reaped by Code officials? Building Performance objectives fulfilled ? – who’s

responsible? Are the designs PEER reviewed at site and design

office? Are the construction quality ensured? Plans are passed but not structural details? Are the building life guaranteed for 50 yrs

atleast? – Lab and field?

Non engineered buildings -Amritsar

Unethical constructions?

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New important constructions Who has designed the structure? What are the seismic design criteria

considered for the building? What is the sub-soil strata at the site? Is there any simulation study done for the

seismic performance of the building? Uniformity of concrete grade, cement

grade, steel grade, water and processing of concrete making – ensured?

List of Indian Standards on Earthquake Engineering + National building Code1. IS 1893 (Part I), 2002: Indian Standard Criteria for

Earthquake Resistant Design of Structures2. IS 4326, 1993: Indian Standard Code of Practice for

Earthquake Resistant Design & Construction of Buildings.

3. IS 13827, 1993: Indian Standard Guidelines for improving Earthquake Resistance of Earthen Buildings

4. IS 13828, 1993: Indian Standard Guidelines for Improving Earthquake Resistance of Low Strength Masonry Buildings

5. IS 13920, 1993 Indian Standard Code of Practice for Ductile Detailing of Reinforced Concrete Structures Subjected to Seismic Forces.

6. IS 13935, 1993: Indian Standard Guidelines for Repair and Seismic Strengthening of Buildings.

Landslides and roads conditions – after Sikkim Earthquake 2011

A dam construction site near Singtam – secondary effect [construction induced LS]

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Geo-professional’s food for action

Earthquake information – IMD reaches to public by FAX after USGS, despite having more than 100 seismographs in place

Strong motion data – questionable integration and timely dissemination among 17+ organisations?

Seismic microzonation of Sikkim – a geologist’s mindgame – very far from true ground reality – ignorance or incapacity or not yet handled by abled geotechnicians?

Earthquake Codes – elegant and accountable to less than 3% of the country’s building stock. Majority in general use more “Steel” than proper “ductile reinforcement”as per IS:13925

Govt. reserves $1.5 billion / yr for up keeping 15000 KM hill roads – where is the economy?

Teesta Urja’s hydel project cost over run shoot up by 300% --yet to start due to Geopolitics

Govt. declared $5 billion aid package but no authentic damage documents yet made acceptable to Central Govt. by Sikkim Govt.

Road Map Masons construct buildings without

knowledge of disaster effects – skill building Enforcement of guidelines, Dev. Control

rules, NBC-2005 etc. – need a separate LAW Estd. Of Mega Civil Works Haat/Mall – where

a citizen gets his house of choice with all agencies under one roof

Disaster museum – e.g. Hiroshima, Kobe Live demonstration of EQ. in a building with

people on board experiencing M-1 to M7.0

Road Map –contd. Seismic observatories in association with

ISRO’s Bhuvan & Gagan mission – GIS mode Live demonstration of Geo-tectonic process

& Landslides, earthquake, Tsunami waves – defining safe vs. vulnerable built environment

Real life Performance of prototype buildings subjected to Flood, cyclone, high winds, fire, ..vis-a-vis good practice in the country

Museum for vernacular structures in the country

“Road map”Where do you think we are lacking?

Knowledge & wisdom? Resources, data, materials? Technological knowhow? Skills & man power? Unforeseen events? …….right

attitude…..commitment…will power?????? …

New act, Law, … New constitutional

amendment???

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Thank you