casita earthquake risk assessment of ahmedabad city network/india/cept/earthquake_risk... · casita...

CASITACASITAEarthquake Risk Assessment Earthquake Risk Assessment

of Ahmedabad Cityof Ahmedabad City

School of Planning,School of Planning,Center for Environmental Planning Center for Environmental Planning

and Technology (CEPT) and Technology (CEPT)

Ajay K Katuri,Ajay K Katuri, Urban PlannerUrban PlannerProf. Prof. MadhuMadhu BhartiBharti, , Urban PlannerUrban Planner

Mr. Mr. AnoopAnoop KaranthKaranth, , Environmental PlannerEnvironmental Planner

2

This work seeks to provide a forecast of the types of losses that the City of Ahmedabad could suffer after an earthquake

The development of the earthquake scenario and consequences are intended for the purpose of emergency planning and preparedness only.The study is very much based on the hypothetical considerations:• the earthquake occurs• the damage potential is based on the output of the loss estimation model and on

experiences from historical earthquakes

3

Urban seismic risk is rapidly increasing in developing countriesUrban seismic risk is rapidly increasing in developing countries where a number of where a number of cities are growing. cities are growing.

►► Risk is typically defined by two components: Risk is typically defined by two components: -- a a hazardhazard (the earthquake) (the earthquake) -- the the assetsassets involved involved

Identification of problems and vulnerable elements is of a primeIdentification of problems and vulnerable elements is of a prime concern in handling concern in handling of disasters. The of disasters. The primary purposeprimary purpose of any effort in disaster mitigation is to of any effort in disaster mitigation is to simplify simplify identification of the physicalidentification of the physical dimensions of riskdimensions of risk reduction rather than disaster reduction rather than disaster prevention. It is therefore prevention. It is therefore “risk management”“risk management” that is being dealt with rather than that is being dealt with rather than disaster preventiondisaster prevention..

►► There is a There is a low probability of recurrence of earthquakeslow probability of recurrence of earthquakes HOWEVERHOWEVER the the Ahmedabad city Ahmedabad city

is under high riskis under high risk because of:because of:-- poor geological hazard assessment and associated vulnerabilitypoor geological hazard assessment and associated vulnerability-- most structures are not seismically designedmost structures are not seismically designed

INTRINTROODUCTIDUCTIOONN

4

Aim The aim of the study is to carry out seismic risk assessment of Ahmedabad and to assist in formulating a Risk Management Plan.

The following aspects is looked upon as part of this study:• Detailed geological hazard assessment• Damage assessment results of 26th January earthquake• Seismic considerations, Planning considerations and Scenario Consequences for existing

urban structures, city infrastructure, emergency activities such as life saving, firefighting, emergency transportation, etc.

The overall aim of the risk mitigation plan is to assist city decision makers on decisions about present infrastructure, existing elements and future development.

Objective The objective of the study is;• to develop an earthquake damage scenario which describes the consequences of a possible

earthquake

5

RADIUS - A Tool for Earthquake Damage Estimation

The United Nations General Assembly designated the 1990s as the “International Decade for Natural Disaster Reduction (IDNDR)” to reduce loss of life, property damage, and social and economic disruption caused by natural disasters.

The IDNDR Secretariat launched the RADIUS (Risk Assessment Tools for Diagnosis of Urban Areas against Seismic Disasters) initiative in 1996.

The tool is a computer programme running on Excel 97, The user needs to input the following information:

• Shape of target region by meshes• Total population and distribution• Total buildings, building types and their distribution• Ground condition (soil type)• Total numbers of lifeline facilities• Choice of scenario earthquake and its parameters

The programme then validates the input data and performs analysis. Output from the analysis includes:

• Seismic (ground shaking) intensity, such as PGA and MMI Intensity• Building damage• Lifeline damage• Casualties, such as number of deaths and injuries• Summary tables and thematic maps showing the result

6

INPUT + INVENTORIES = OUTPUTS

Process of Damage Estimation

R s.

Scenario Earthquake

Ground Motion

Earthquake Disaster Reduction Planning§ Preparedness§ Emergency

Planning§ Recovery

Damage Estimation

Earthquake Hazard

Demographic data, Bldg & Lifeline Inventory,Vulnerabilities

Data

7

Surface Ground Amplification

0.0

0.5

1.0

1.5

Hard Rock Soft Rock Medium Soil Soft Soil

Rock/Soil Type

Am

plifi

catio

n Fa

ctor

Surface ground amplification for various soil type

Soil Condition:Classification or zoning of ground conditions is important in the earthquake damage estimation process because ground conditions directly affect seismic amplification of ground shaking. When classifying ground conditions, vast amount of soil data are required. This Tool adopts a simple classification, which divides the ground into 4 classes with corresponding amplification factors.

8

Building Damage:

This Tool uses the following 10 classification categories, adopted by sample Latin American countries. This classification was determined based on the building material, construction type, applied code, usage and number of stories, etc.

U R M is U n-R einforced M asonry and R C is R ein forced C onc rete build ing

R ES3--- U R M -R C com pos ite cons truc tion - old, deteriorated cons truc tion, not com plying w ith the lates t code provis ions . H eight 4 - 6 s tories .

R ES4--- E ngineered R C cons truc tion - newly cons truc ted m ulti-s toried bu ild ings , for res idential and comm erc ial purposes .

E DU1--- S chool buildings , up to 2 s tories .

usually percentage should be very sm allE DU2--- S chool buildings , greater than 2 s tories .

usually percentage should be very sm allM ED1--- Low to medium ris e hosp itals

usually percentage should be very sm allM ED2--- H igh r ise hospitals

usually percentage should be very sm allC OM ---- S hopping C entersIND ----- Indus trial fac ilities , both low and h igh r isk

B uild ing C lasses E xp la nation

U R M -R C com pos ite cons truc tion - sub-s tandard cons truc tion, not com plying w ith the local code provis ions . H eight up to 3 s tories .

Inform al cons truc tion - m ain ly s lum s, row hous ing etc . m ade from unf ired bricks , mud mortar, loosely tied walls and roofs .

R ES2---

R ES1---Building Damage Curve

0

20

40

60

80

100

4 5 6 7 8 9 10 11 12MMI

Dam

age

Rat

e (%

)

RES1 RES2 RES3 RES4 EDU1 EDU2MED1 MED2 COM IND

Building Damage Curve (Damage Rate in % to MMI)

9

Lifeline Damage:

Lifeline facilities include water, sewage, electric power, gas supplies and transportation networks, namely roads and bridges, etc Vulnerability curves for each lifeline are determined as the function of acceleration/MMI based on observed damage to lifeline facilities in past sample earthquakes.

Lifeline Damage Curve

0

20

40

60

80

100

4 5 6 7 8 9 10 11 12MMI

Dam

age R

ate (%

)

Road1 Road2 BridgeTunnels Electric1 Electric2Water1 Water2 Water3Reservoir1 Reservoir2 Gasoline

Lifeline Damage Curve (Damage Rate in % to MMI)

10

A. GEOLOGY AND SEISMOLOGYB. SCENARIO EARTHQUAKE DEVELOPMENT

Part Part 11TTHE SCENARIHE SCENARIOO EARTHQUAKEEARTHQUAKE

11

A. GEOLOGY AND SEISMOLOGY

Figure indicates the location, year and number of fatalities (in parenthesis) for earthquakes in India in the past 200 years (Bilham and Gaur, 2000).

Seismic Hazard and Vulnerability

a More than 100,000 fatalities from earthquakes have occurred on the Indian Plate in the past two centuries. b The rate of occurrence of fatal earthquakes in the past two decades is more than double its mean value in the past two centuries

13

Earthquake Hazard in Gujarat

Seismic Zoning Map of India Earthquake Zone Area Hazard Map of Gujarat

MMI IX19%

MMI VIII14%

MMI VII66%

14

Figure Seismic Hazard Map India. Figure shows the peak ground acceleration (PGA) that a site can expect during the next 50 years with 10 percent probability (Source: www.geology.about.com)

Seismic Hazard Zonation

15

Seismicity in India,

Relative depths of occurrence

16

Scenario Earthquake

Earthquake Scenarios describe the expected ground motions and effects of specific hypothetical large earthquakes. In planning and coordinating emergency response, utilities, emergency responders, and other agencies are best served by conducting training exercises based on realistic earthquake situations, ones that they are most likely to face. The potential shaking effects is the main benefit of the earthquake scenario for planning and preparedness purposes.

Past Earthquake Damage in Ahmedabad

Several high-rise buildings collapsed in Ahmedabad killing close to 800 persons during the last Bhuj Earthquake.

The city on the eastern side of the river has mostly 3 or 4 storey brick buildings with load bearing walls which virtually received no damage, except for cracks in walls, even though the building and population densities are high. The western side of the city has mostly 5 (ground + four) and a large number of ten storey buildings, whereas in the south-east most of the buildings are 5 storey. Several thousand buildings were damaged in the town to various degrees.

B. SCENARIO EARTHQUAKE DEVELOPMENT

17

Satellite image (IRS IC LISS – III) of Ahmedabad (January 1996) showing palaeochannel, lakes and damaged area during 26th January Bhuj earthquake, Source: ISRO

The relation of damage pattern to location of paleochannels of the Sabarmati river can be seen in the IRS LISS III imagery of the city.

•The paleochannel in the picture is seen as a small faint white loop, 4 – 5km west of the present river course. Some of the collapse buildings in the western part of the town lie within the zone bound by the past and present courses of the river.

•Thus poor soil condition, presence of water and Basin Edge effect may have contributed to more damage in their proximity.

•Inference: geological conditions, and site amplification, damage.

18

Pattern of collapsed buildings in Ahmedabad, showing that they lie in a linear pattern and in a group of clusters. The five biggest clusters (consisting of 5 to 8 buildings) are identified by a circle. Most of the collapsed buildings lie in three bands, which are about 200m and 1.2 km in width.

(Source: Damage pattern due to January 2001 Bhuj earthquake, India by N.Bhandari and B.K.Sharma, Physical Research Laboratory, Ahmedabad)

19

Geology of Ahmedabad

• Ahmedabad city is locatedon 3km to 4km thick sandstone, clay and alluvium soil of Sabarmati river within the CambayGraben.

• The Deccan basement, generally found in the adjacent Cambay basin at 4 to 5km depth is missingat Ahmedabad and the hardrock basement of granite rocks occur at the depth of about 7-8km.

• The upper 200 – 300mbelow the Ahmedabad city is mostly alluvium, formed by the meandering Sabarmati river in the past

Deep section along Mehmedabad– Nadiad region (modified after, Kaila et al., 1981)

Cross section of a Sedimentary column at Ahmedabad – Paldi (after Bhandari et al., 1986)

20

Location of Ahmedabad in the Cambay rift zone(Source: Seismotectonics Atlas, Geological Survey of India, 2000).

Structural Map of Ahmedabad oil field and vicinity showing two faults running east and west of Ahmedabad trending NNW to SSE. (Source Kumar et al 2000)

21

Soil Conditions

Source: Revised draft development plan of AUDA – 2011 AD. Part – 1 Surveys, Studies and Analysis.

Soil depth and texture map of Ahmedabad and its environs

Based on this, the type of soil for the city is considered to be of “Soft Soil” type.

Corresponding to soft alluvial soil, reclaimed land and landfill etc., the soil is assigned with a amplification factor of 1.3.

22

Choosing an Appropriate Earthquake Scenario

Figure showing the Scenario Earthquake Epicenter at the junction of Marginal Faults intersection, one of CambayGraben and the other of Narmada Graben. Hypocenter of Scenario Earthquake falls in the city of Bharuch which is about 150kms from Ahmedabad.

Scenario 1

23

Case Location Epicentre Distance (in kms)

Magnitude Depth (in km)

Time __:__hrs

Casualty inthe city

1 Bharuch 150 7 12 0:00 37662 Bhuj 300 7.7 22 8:46 0

26th Jan Earthquake* 300 7.7 22 8:46 7463 Ahmedabad 30 7 12 0:00 21502

* realistic death figure in the city of Ahmedabad during 26th January Bhuj earthquake. Also note the difference in the figure of death when the simulation was done taking the same parameters.

Scenario 2

Figure showing the Scenario Earthquake Epicenter on the Marginal Faults defining the Cambay Graben. Epicenter of Scenario Earthquake falls 30 kms North West of Ahmedabad.

24

Part Part 22GGENERAL CENERAL COONSEQUENCES NSEQUENCES OOF THEF THE

SCENARISCENARIOO EARTHQUAKEEARTHQUAKE

A. PROFILE OF THE STUDY AREAB. INDRODUCTION TO THE CONSEQUENCESC. ESTIMATION OF ELPD. GROUND MOTIONE. MASS CASUALTY SIMULATIONF. BUILDINGS AND STRUCTURESG. EMERGENCY FACILITIES AND RESPONSEH. TRANSPORTATION SYSTEMSI. COMMUNICATIONSJ. LIFELINE UTILITIES

Sub topics looked in terms of General Characteristics, Seismic Considerations, Planning Considerations and Scenario Consequences

25

A. PROFILE OF THE STUDY AREAAMRAPUR

KOTHANAVA

NAROLACHARADA

NADRA

AMJA

CHANDISAN

BARMUVD

UMEDPURA

GOKADPUR

NANI TIBLI

PAHADI

JALAMPURGODASAR

RATANPUR

AKALACHHA

SUNDHA

SAYALA

City Area: 190.84 sq.km (AMC limits)

Geology: Falls in alluvial tract and comprises mostly quaternary thick alluvial and blown sand

Hydrogeomorphology: The study area falls under Alluvial Plain (reclaimed) type. Comprises vast alluvial tract supporting the main urban population

Paleochannel: Probable presence of palaeochannel of a past tributary of the Sabarmati river

Soil: Built-up land.

Surface Water Bodies: River Sabarmati and several important lakes and talavadis (many are backfilled)

Geology Settings: Lies in two Marginal Faults and also on the intersection of two Minor Lineaments

26

South Zone

East Zone

North Zone

Cantonment

Sabarmati River

West Zone

Central Zone

Figure Zone location in AMC area

27

Population: 35,15,361 (AMC)

Density: 18,421(persons/sq.km)

Municipal Infrastructure:• Health Facilities

Total number of beds – 4782 beds

• Fire Department

10 fire stations (avg. 35 persons per fire station)

• Education Institutions

Total numbers – 1727

• Transportation

Road, Railway and Air Transport

• Water Supply

Network – 2543 km, Distribution Stations – 78,

Terminal Reservoirs and ESR – 41

• Sewerage

Network – 1345 km, Pumping Stations – 38,

STP – 2 (and two under construction)

28

• Communication

Telephone Exchange Buildings – 42

Transmission Towers – 35

• Electricity

Number of Electrical Sub station – 13

Major Electrical Transmission Tower – 492

Housing

Total Housing Stock 10.50 lakhs

29

Study Area

The area is divided into 58 blocks and each block consists of 40 cells of 250m X 250m each

Total area: 118.5 sq.km

Total cells: 1895 cells of 250m X 250m each

City Map of Ahmedabad Source: SETU City Map, SETU Publications 1988, Map prepared by SETU CYBERTECH PVT Ltd.

30Figure Division of the SETU Map into 1895 cells of 250m X 250m each

31

## ## ## ## ## ##

## ## ## ## ## #### ## ## ## ## ## ## ## ## ## ##

## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## #### ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##

## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## #### ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## #### ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##

## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## #### ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## #### ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## #### ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##

## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##93 ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##94 ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##

52 72 95 ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##34 53 73 96 ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##

17 35 54 74 97 ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##1 18 36 55 75 98 ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##2 19 37 56 76 99 ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##3 20 38 57 77 ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##4 21 39 58 78 ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##5 22 40 59 79 ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##6 23 41 60 80 ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##7 24 42 61 81 ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##8 25 43 62 82 ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##9 26 44 63 83 ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##10 27 45 64 84 ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##11 28 46 65 85 ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##12 29 47 66 86 ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##13 30 48 67 87 ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##14 31 49 68 88 ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##15 32 50 69 89 ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##16 33 51 70 90 ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##

71 91 ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##92 ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##

## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## #### ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## #### ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##

## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## #### ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##

## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## #### ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##

## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## #### ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## #### ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## #### ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##

Soil Type Distribution Map as an input map of RADIUS

D e s c r i p t i o n

U n k n o w nH a r d R o c kS o f t R o c k2

0

V a l u e R a n g e f o r C o l o r

1

S o f t S o i lM e d i u m S o i l3

4

32

Scenario Consequences

Mesh weight distribution map

Very HighVery High44

HighHigh33

AverageAverage22

LowLow11

NoneNone00

Mesh Mesh WeightWeight

ValueValueRangeRange

for for meshmeshColorColor

33

Figure shows the probable intensity distribution for all the three magnitudes M6, M6.5 and M7

ToToFromFromToToFromFromToToFromFrom

7.787.787.327.326.796.79Avg Avg MMIMMI

8.08.07.97.97.67.67.47.47.07.06.96.9

6.96.9

6.86.8

6.76.7

0.11g0.11g

6.86.8

6.76.7

6.56.5

RangeRange

M 6*M 6*

7.47.4

7.37.3

7.27.2

0.16g0.16g

7.37.3

7.27.2

7.17.1

RangeRange

M 6.5M 6.5

0.22g0.22gAvg Avg PGAPGA

7.97.97.87.8

7.87.87.77.7

7.77.77.67.6

RangeRange

M 7 M 7

Color Color IDID

* Many of the results for M6 of the scenario earthquake show similar results when compared to the last Bhuj Earthquake.

34

E. MASS CASUALTY SIMULATIONEstimated number of people killed and injured in Ahmedabad cityTotal Day Population 3566829 Total Night Population 3550000

Magnitude Time of occurrence

Total death population

Total severely injured

Total moderately injured

Total injured

M 6 00:00 hrs 1251 2989 44638 47627 M 6 12:00 hrs 923 2608 41037 43644

M 6.5 00:00 hrs 7233 17475 114805 132280 M 6.5 12:00 hrs 4775 12707 91888 104595

M 7 00:00 hrs 21502 51795 204587 256382 M 7 12:00 hrs 13679 36228 149050 185279

Magnitude Total population

Total death population

% of total population

Total injured % of total population

M6 (00:00hrs) 3550000 1251 0.035 47627 1.34 M6 (12:00hrs) 3566829 923 0.026 43644 1.23 M6.5 (00:00hrs) 3550000 7233 0.20 132280 3.73 M6.5 (12:00hrs) 3566289 4775 0.13 104595 2.9 M7 (00:00hrs) 3550000 21502 0.61 256382 7.22 M7 (12:00hrs) 3566829 13679 0.38 185279 5.22

Casualty estimation in terms of percentage

35

Casualty (death) distribution (Magnitude M 7, Time of occurrence 00:00hrs) Total death: 21502 (0.61% of total population)

38382828

28281919

191999

9900

ToToFromFrom

RangeRangeColor Color IDID

36

574574431431

431431287287

287287144144

14414400

ToToFromFrom

RangeRangeColor Color IDID

Casualty (injured) distribution. (Magnitude M 7, Time of occurrence 00:00hrs)Total injured: 256382 (7.22% of total population)

37

F. BUILDINGS & STRUCTURES

BUILDINGS

Building vulnerability is critical to earthquake risk.

Collapsed buildings caused about three quarters of all earthquake fatalities during the 20th century.

The risks associated along with it are both structural and nonstructural risks.

The effects of an earthquake on buildings and structures depend on many variables, including:• Size of the earthquake• Depth of the earthquake• Geologic and soil characteristics of the site• Severity and duration of ground shaking• Code provisions used in the buildings design• Structural System failure• Building construction type, configuration and size• Quality of construction• Proper building maintenance

Reinforced concrete frame with unreinforced masonry infills is the most common structural system for RC buildings in Ahmedabad (View of Ahmedabad 2 km to the Southwest of the airport).

38

1%1%Non EngineeredNon Engineeredincludes buildings constructed with includes buildings constructed with materials like grass and thatchmaterials like grass and thatch

Category XCategory X

4%4%EngineeredEngineeredconsists of consists of reinforced concretereinforced concrete and welland well--constructed wooden buildingsconstructed wooden buildings

Category CCategory C

71%71%Less EngineeredLess Engineeredbrick buildings fall under this category. brick buildings fall under this category. Category BCategory B

24%24%Non EngineeredNon Engineeredbuildings made of fieldstones, unbuildings made of fieldstones, un--burnt burnt bricks and clay structuresbricks and clay structures

Category ACategory A

Building blocks Building blocks -- Urban Urban House in AhmedabadHouse in Ahmedabad

Engineering Engineering ClassificationClassification

DetailsDetailsCategoryCategory

Building blocks – urban house in Ahmedabad

Source: : Towards a culture of Safer Building Practices — by Rajib Shaw, United Nations Centre for Regional Development, Kobe-Japan

39

Example of a soft-story apartment building (Photograph by Goel)

Example of overhang at upper floors in residential construction (Photograph by Goel)

Structural System Deficiency

Figure Floating columns in upper stories along perimeter of buildings to optimize FSI requirements, lead to irregularities in load transfer paths in elevation (Source: Reinforced Concrete Structures, Earthquake Spectra 2001 Bhuj, India Earthquake Reconnaissance Report, Supplement A To Volume 18, July 2002)

40

Shearing of unsupported corner column, Mehta Chambers

Crushing and spalling of concrete close to the beam bottom, Tagore Park Society.

No lateral load force transfer mechanism to the core, Punjal Apartments

Poor quality construction material, Neelima Park Apartments

Structural Damage

41

Damaged multistory building (Manasi complex) in Ahmedabad (soft story ground floor with rigid beams and weak columns).

Building with unsymmetrical plan due to infill walls, Apollo Apartments

42

Half of the building pulled away from the elevator core that formed the shear core of the building

Poor quality of concrete (Photograph by Goel)

Part of the building fell on the neighboring building indicating presence of torsionalmotions (Photograph by Goel)

43

MED10.20%

EDU10.65%

EDU21.14%

MED20.32%

COM6.28%

IND7.99%

Res120.80%

Res237.75%

Res320.76%

Res44.11%

Building stock in terms of percentage for the city of Ahmedabad (RADIUS default building type)

URM is Un-Reinforced Masonry and RC is Reinforced Concrete building

RES3--- URM-RC composite construction - old, deteriorated construction, not complying with the latest code provisions. Height 4 - 6 stories.

RES4--- Engineered RC construction - newly constructed multi-storied buildings, for residential and commercial purposes.

EDU1--- School buildings, up to 2 stories.

usually percentage should be very smallEDU2--- School buildings, greater than 2 stories.

usually percentage should be very smallM ED1--- Low to medium rise hospitals

usually percentage should be very smallM ED2--- High rise hospitals

usually percentage should be very smallCOM ---- Shopping CentersIND ----- Industrial fac ilities, both low and high risk

Building Classes Explanation

URM-RC composite construction - sub-standard construction, not complying with the local code provisions. Height up to 3 stories.

Informal construction - mainly slums, row housing etc. made from unfired bricks, mud mortar, loosely tied walls and roofs.

RES2---

RES1---

44

Building Distribution in Map

400400300300

300300200200

200200100100

10010000

ManualManualRangeRangeColor IDColor ID

45

Damage building distribution for magnitude M 7

1221229292

92926161

61613131

313100

ToToFromFrom

RangeRangeColor IDColor ID

M 7M 7M 6.5M 6.5M 6M 6DAMAGE SUMMARYDAMAGE SUMMARY

24.15%24.15%15.38%15.38%7.86%7.86%--Percentage damage of buildingsPercentage damage of buildings

12074812074876914769143933339333500000500000Total number of damaged buildingsTotal number of damaged buildings

46

0

5

10

15

20

25

30

35

RES1 RES2 RES3 RES4 EDU1 EDU2 MED1 MED2 COM IND

Building Type

Perc

enta

ge d

amag

e

M 6 M 6.5 M7

Damage count of individual type for magnitudes of M6, M6.5 and M7

47

M 6

M 6.5

M 7

damage area

Location of buildings in groups where there is possibility of maximum damage to buildings from the scenario earthquake.

48

Overlap showing the damage buildings for magnitude M7 with the existing land use

50

Scenario Consequences – School Buildings

21.85%21.85%14.88%14.88%8.48%8.48%56995699EDU2EDU2

12.96%12.96%8.32%8.32%4.40%4.40%32713271EDU1EDU1

Individual Individual damage count damage count for M7for M7

Individual Individual damage count damage count for M6.5for M6.5


Total Total building building countcount

CategoryCategory

Estimated percentage of school buildings damaged for each category

6,51,0656,51,065715715Private PrimaryPrivate Primary

2,0052,00555Municipal SecondaryMunicipal Secondary

54,21854,218226226Private SecondaryPrivate Secondary

1,68,1151,68,115210210Private Higher SecondaryPrivate Higher Secondary

1,7801,78088OthersOthers

2,06,9492,06,949563563Municipal PrimaryMunicipal Primary

Number of Number of StudentsStudents

Number of Number of SchoolSchoolType of SchoolType of School

Existing Education Institutions

51

22Mobile DispensariesMobile Dispensaries

13171317Private registered Nursing homesPrivate registered Nursing homes2020DispensariesDispensaries

22Super Super SpecialitySpeciality CentresCentres33Dental clinicsDental clinics

222222AanganwadisAanganwadis88Maternity HomesMaternity Homes

55Pathological LaboratoryPathological Laboratory55Referral HospitalReferral Hospital

3636Urban Health CentreUrban Health Centre11Infectious Disease HospitalInfectious Disease Hospital

11Naroda TB Hospital (ESSI)Naroda TB Hospital (ESSI)11T.B.HospitalT.B.Hospital

11Bapunagar Gen. (ESSI)Bapunagar Gen. (ESSI)11Ophthalmic HospitalOphthalmic Hospital

11Civil hospitalCivil hospital33General HospitalGeneral Hospital

Nos.Nos.Type of HospitalType of HospitalNos.Nos.Type of HospitalType of Hospital

Medical Facilities by othersMedical Facilities by othersMedical Facilities by AMCMedical Facilities by AMC

Existing Hospital systems and Medical Facilities

Total number of beds: 4782 nos

Medical Facilities in the city

52

1852791852791490501490503622836228136791367912:00 hrs12:00 hrsM 7M 7

2563822563822045872045875179551795215022150200:00 hrs00:00 hrsM 7M 7

104595104595918889188812707127074775477512:00 hrs12:00 hrsM 6.5M 6.5

13228013228011480511480517475174757233723300:00 hrs00:00 hrsM 6.5M 6.5

436444364441037410372608260892392312:00 hrs12:00 hrsM 6M 6

47627476274463844638298929891251125100:00 hrs00:00 hrsM 6M 6

Total injuredTotal injuredTotal moderately Total moderately injuredinjured

Total severely Total severely injuredinjured

Total death Total death populationpopulation

Time of Time of occurrenceoccurrence

MagnitudeMagnitude

35500003550000Total Night PopulationTotal Night Population

35668293566829Total Day PopulationTotal Day Population

Estimated number of people killed and injured in Ahmedabad city

21.27%21.27%14.24%14.24%8.54%8.54%15801580MED2MED2

17.17%17.17%11.58%11.58%7.09%7.09%10021002MED1MED1


Individual Individual damage count damage count for M6.5for M6.5


Total building Total building countcount

CategoryCategory

Scenario Consequences – Medical Facilities

Estimated percentage of hospital buildings damaged for each category

Available beds after an occurrence of earthquake is probably (say) 1700nos out of 4782 nos.

53

Medical Care Capability and Emergency Response Contribution

GESI result for Ahmedabad City's Risk Distribution

22.6%

53.2%

0.8%

23.4%

Building Collapse

Search & RescueProblems

Emergency ResponseProblems

Medical CareProblems

54

Scenario Consequences – Transport System

4.74.759.259.20.220.227.787.78M 7M 7

3.13.138.838.80.160.167.327.32M 6.5M 6.5

1.61.620.320.30.110.116.796.79M 6M 61272 km1272 kmLength of local roadsLength of local roads

Damage Damage Ratio (%)Ratio (%)

Damage Damage NumberNumber

Average Average PGA (g)PGA (g)

Average Average MMIMMI

MagnitudeMagnitudeTotal countTotal countLifelineLifeline(Road 1)(Road 1)

Estimated road network damage

8.38.30.60.60.220.227.787.78M 7M 7

6.06.00.40.40.160.167.327.32M 6.5M 6.5

3.53.50.20.20.110.116.796.79M 6M 677

Number of Major Number of Major Transportation Bridge Transportation Bridge (Road and Rail)(Road and Rail)





MagnitudeMagnitudeTotal countTotal countLifelineLifeline(Bridges)(Bridges)

Estimated transportation bridge damage

55

Scenario Consequences – Telephone Communication System

2.42.40.820.820.220.227.787.78M 7M 7

1.81.80.620.620.160.167.327.32M 6.5M 6.5

1.11.10.380.380.110.116.796.79M 6M 63535

Number of Major Number of Major Telecommunication Telecommunication Transmission TowerTransmission Tower





MagnitudeMagnitudeTotal countTotal countLifelineLifeline(Electric1)(Electric1)

Damage estimation for transmission towers

Damage estimation for telephone exchange substations

18.218.27.637.630.220.227.787.78M 7M 7

13.413.45.655.650.160.167.327.32M 6.5M 6.5

9.09.03.813.810.110.116.796.79M 6M 64242

Number of TeleNumber of Tele--communication communication SubstationSubstation





MagnitudeMagnitudeTotal countTotal countLifelineLifeline(Electric 2)(Electric 2)

56

2.42.411.5711.570.220.227.787.78M 7M 7

1.81.88.788.780.160.167.327.32M 6.5M 6.5

1.11.15.415.410.110.116.796.79M 6M 6492492

Number of Major Number of Major Electrical Electrical Transmission TowerTransmission Tower





MagnitudeMagnitudeTotal Total countcount

LifelineLifeline(Electric1)(Electric1)

18.218.22.362.360.220.227.787.78M 7M 7

13.413.41.741.740.160.167.327.32M 6.5M 6.5

9.09.01.181.180.110.116.796.79M 6M 61313

Number of Electrical Number of Electrical SubstationSubstation

Damage Ratio Damage Ratio (%)(%)





LifelineLifeline(Electric 2)(Electric 2)

Damage estimation

Damage estimation for electrical substations

Scenario Consequences – Electricity Transmission System

57

3.93.91.591.590.220.227.787.78M 7M 7

2.52.51.021.020.160.167.327.32M 6.5M 6.5

1.21.20.490.490.110.116.796.79M 6M 641 nos41 nos

Number of Number of Elevated Storage Elevated Storage TanksTanks

5.95.96.196.190.220.227.787.78M 7M 7

4.94.95.145.140.160.167.327.32M 6.5M 6.5

3.53.53.673.670.110.116.796.79M 6M 6105 nos105 nos

Number of Storage Number of Storage ReservoirsReservoirs

6.06.00.120.120.220.227.787.78M 7M 7

4.44.40.0880.0880.160.167.327.32M 6.5M 6.5

2.92.90.0580.0580.110.116.796.79M 6M 62 nos2 nos

Number of Water Number of Water Treatment PlantTreatment Plant

10.510.52.412.410.220.227.787.78M 7M 7

7.77.71.771.770.160.167.327.32M 6.5M 6.5

5.15.11.171.170.110.116.796.79M 6M 623 nos23 nos

Number of Water Number of Water Pumping StationsPumping Stations

1.71.743.7043.700.220.227.787.78M 7M 7

1.11.128.2328.230.160.167.327.32M 6.5M 6.5

0.60.614.0814.080.110.116.796.79M 6M 62543km2543km

Length of Major Length of Major Water Distribution Water Distribution LineLine






LifelineLifeline(Water 1)(Water 1)

Scenario Consequences – Water Distribution System

Damage estimation of water systems

58

Damage estimation of sewage systems

Scenario Consequences – Sewerage System

6.06.00.240.240.220.227.787.78M 7M 7

4.44.40.170.170.160.167.327.32M 6.5M 6.5

2.92.90.110.110.110.116.796.79M 6M 64 nos4 nos

Number of Sewage Number of Sewage Treatment PlantTreatment Plant

10.510.53.993.990.220.227.787.78M 7M 7

7.77.72.922.920.160.167.327.32M 6.5M 6.5

5.15.11.941.940.110.116.796.79M 6M 638 nos38 nos

Number of Sewage Number of Sewage Pumping StationsPumping Stations

1.71.722.8622.860.220.227.787.78M 7M 7

1.11.114.7914.790.160.167.327.32M 6.5M 6.5

0.60.68.078.070.110.116.796.79M 6M 61345km1345km

Length of Major Length of Major Sewage Trunk Sewage Trunk Distribution LineDistribution Line






LifelineLifeline(Water 2)(Water 2)

59

17.417.47.87.80.220.227.787.78M 7M 7

11.811.85.35.30.160.167.327.32M 6.5M 6.5

6.56.52.92.90.110.116.796.79M 6M 645nos45nosNumber of Number of

Gasoline StationsGasoline Stations



Average PGA Average PGA (g)(g)



LifelineLifeline(Gasoline)(Gasoline)

Scenario Consequences – Petroleum Stations

Damage estimation of petroleum stations

60

Proposed course Outline

• Name of the course: Risk Management for Urban Development

• Status: Elective• Duration: 14 weeks• Credits: 4 (2hr/week) • Mode of evaluation: Assignments, Case

studies, End exam

61

Target Schools and Programs

Center for Environmental Planning and Technology (CEPT)

• School of Planning

• Masters in Urban and Regional Planning, Environmental Planning and Housing (45 students)

• School of Building Science and Technology

• Construction Project and Management (Masters) (10 students)

• Structural Design (Masters) (10 students)

Center for Excellence for Environment and Sustainable Development (CEED)

• Urban Management (PG Diploma) (15 students)

62


• Session 1- 4 Introduction to Hazards and Related Risks

• Definition to Hazards

• Types and extent and vulnerability

• Session 5- 8 Vulnerability Assessment

• RADIUS, ILWIS/ArcGIS

63


• Session 9- 13 Geo-Information systems for Hazard Managements

• Spatial databases Management Systems

• Relational Database Management Systems

• ILWIS, ArcView, ArcGIS, ERDAS

• Session 14- 19 Damage and Loss Assessment

• Existing Damage and Loss Assessment Mechanisms

• HAZUS, ECLAC, other models to be developed

64


• Session 20- 25 Risk Management and policy contribution

• Safe Practices and Policies

• Standard Building Codes and practices

65

Thank you

casita earthquake risk assessment of ahmedabad city network/india/cept/earthquake_risk... · casita...

Documents