Earthquake Risk in Bangladesh

Prof.Dr.Engr.M.Jahangir AlamChittagong University of Engineering & Technology, Bangladesh

www.cuet.ac.bd

EERC

Lecture Contents:

Brief Introduction to Bangladesh

Disaster-Earthquake Hazard

Earthquake Hazard identification

Earthquake Vulnerability Assessment

Earthquake Risk Quantification

Earthquake Risk Reduction Strategies

Earthquake Master Plan for Bangladesh

BANGLADESHThe Peoples Republic of Bangladesh

Total Boundary Area-147,570Km2

Total Population-More than 150M

Population density in Major Cities:Dhaka (Capital) - 80,000/Km2

Chittagong (Port City) - 25,000/Km2

Sylhet - 18,000/Km2

Bangladesh Faces Disasters

Bangladesh is a MEGA Shopping Center for

DISASTERS !!

Rural Flood

Urban Flood

Cyclonic Surge

Cyclone

Landslide

Landslide

Earthquake

Earthquake

DISASTER

Why Deal with Disasters ?

TYPES OF DISASTER

Bangladesh

Video on Disaster - Bangladesh Flood-1

Cyclone SIDR-Bangladesh

Earthquake-Tsunami-JAPAN

RECENT DISASTERS around the World

Landslide-Bangladesh

Flood-Bangladesh

DISASTER TREND

The trend curves verify the increase in catastrophe losses due to disasters since 1950

Climate Change

Hazard: Earthquake

Earthquake !

It is not earthquake, but vulnerable structures kill people !

Killing School Children!!

Mass graveyard during Pakistan Earthquake!!

After China Earthquake

Impact of Earthquakes

Japan 2011-??

China Earthquake-2008 Lesson Learnt From Real-time Earthquake Experiments!!!

Magnitude was 7.9 in RS

Landslide ! Very Similar to Bangladesh

Landslide ! Very Similar to Bangladesh

Landslide !

Landslide !

Traditional Building Collapse !

Traditional Building Collapse !!

Engineered Vs Non-Engineered Construction !!

Liquefaction Issues at Building Site !!

Liquefaction Problem !!

Damage to Brick Buildings

Buildings without Seismic Provisions

Liquefaction Problems !

School Buildings Collapsed

Newly Built Apartment without Seismic provisions

Intact Buildings with Seismic Provisions

Damage to Transmission Line and Electric Sub-station due to Liquefaction during 1999-Taiwan Earthquake

Damaged Sea Port due to Liquefaction during Taiwan 1999 Earthquake

Failure of DAM during 1999 Taiwan Earthquake

DAM Failures in China During 2008 Earthquake

Bangladesh Sources of Earthquake Hazard

Tectonic Plate Boundaries around BANGLADESH & INDIA

TECTO

NIC

MA

P OF B

AN

GLA

DESH

Seism

ic Fault Line inside Chittagong

SeismicitySeismicity of Central Asiaof Central Asia

Andam

an Earthquake of 7.6M-2009

BIG PAST EARTHQUAKES NEAR BANGLADESH

INDIAN SEISMIC MAP

SEISMIC MAP OF BANGLADESH

Tectonic Plates near Bangladesh

Animation of Tectonic plate movement from Prof.Akhter of Dhaka University

Sources of earthquakes in Bangladesh

Sources of Earthquakes in Bangladesh

Earthquake Scenarios Earthquake Scenarios

Earthquake Fault Zones

Five Earthquake Scenarios by OIC

3 scenarios per city(1)The worst of all five scenarios

(2) A moderate one representing the remaining four scenarios

(3) A magnitude-6 earthquake occuringunderneath the city

1997 Earthquake, M=6.0Bangladesh-Myanmar Border

Collapse of Buildings in Chittagong (100 km from Epicenter)

EARTHQUAKE IN CHITTAGONG & RANGAMATI EARTHQUAKE IN CHITTAGONG & RANGAMATI ON JULY 27, 2003.ON JULY 27, 2003.

Earthquake Magnitude = 5.6RS

Focal Depth = 10Km

Intensity = VII-VIII in EMS

GEOLOGY & TECTONIC FEATURESGEOLOGY & TECTONIC FEATURES

•• Hills occupy almost 80 Hills occupy almost 80 percent of the area percent of the area

•• Other parts: Other parts: KaptaiKaptai lake & lake & KarnafuliKarnafuli river river

•• Several Faults & Several Faults & Lineaments exist Lineaments exist

•• A major fault exist A major fault exist several kilometer east several kilometer east of the of the epicentralepicentral areaarea

LAKER’S PUBLIC SCHOOL, RANGAMATI

LAKER’S PUBLIC SCHOOL, RANGAMATI

ARMY CAMP, RANGAMATI

BDR CLUB, KALABUNIA, RANGAMATI

HEALTH COMPLEX, KALABUNIA, RANGAMATI

NIKCHENDRA NIKCHENDRA PRIMARY PRIMARY SCHOOL, SCHOOL,

KALABUNIA, KALABUNIA, RANGAMATIRANGAMATI

MUD HOUSE, KALABUNIA, RANGAMATIMUD HOUSE, KALABUNIA, RANGAMATI

ARMY STAFF QUARTER, RANGAMATI

PUBLIC LIBRARY BUILDING, CHITTAGONG

PUBLIC LIBRARY, CHITTAGONGPUBLIC LIBRARY, CHITTAGONG

CHITTAGONG POLYTECHNIC STAFF QUARTER CHITTAGONG POLYTECHNIC STAFF QUARTER (D(D--TYPE), CHITTAGONGTYPE), CHITTAGONG

CHITTAGONG POLYTECHNIC STAFF QUARTER CHITTAGONG POLYTECHNIC STAFF QUARTER (B(B--TYPE), CHITTAGONGTYPE), CHITTAGONG

Liquefaction Potential Study of Chittagong City

Study Area: 41 Administrative Wards Covering 200 Sq. Km.

Study Based on STANDARD PENETRATION TEST values.

Liquefaction Potential Map of Chittagong Generated Using Japan Road Association Code and Seed Simplified Method and Correlated.

EERC

Chittagong Sea Port Area…….EERC

Chittagong Sea Port Jetties…….EERC

Liquefaction Potential Map of Chittagong City

EERC

Liquefiable Zones in Chittagong !!

Highly Susceptible to Liquefaction

Sea Shore and Flood Plain Area

River Side Area

EERC

Critical Installations at Risk due to Liquefaction !!

Chittagong Sea Port

Chittagong Air Port

Chittagong and Karnafully Export Processing Zone(BEPZA)

Petrochemical Industries mainly, refineries

Sikhalbaha Power Station(60MW)

Industries (Garments,Cement,Salt & other industries)

Chittagong Ring Main Gas Line

Greater Chittagong Power Distribution Sub-Stations

EERC

Petroleum Oil Refineries at Seismic Risk in Chittagong

SEISMIC VULNERABILITY NEEDS TO BE ASSESSED !

Chittagong Sea Port at Seismic Risk in Chittagong

SEISMIC VULNERABILITY NEEDS TO BE ASSESSED !

Chittagong Hill Tract Hydro Power Station

Seismic Safety Assessment of Hydro Power Station is needed

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S TRA

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ISSION

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CITYGATE DRS

NASIRABAD DRS

KALURGHAT DRS

EPZ DRS

KAFCO CUFL

ERL

TSP

KPM

RAUZANPOWER PLANT

CUET

TOW

A RD

S KA

P TAI

HALISHAHAR ROAD

CD

A R

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D

RAILWAY ROAD

COU RT ROAD

PAT

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ILLA BAKHRABAD

HATHAZARI

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SITAKUNDA

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Nasirabad Zone

Kalurghat Zone

Port conn ecti ng road

Bakalia

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ooring r o

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Waterbody.shp3 inch.shp4 inch.shp6 inch.shp8 inch.shp10 inch.shp12 inch.shp16 inch.shp20 inch.shp24 inch.shp

# Drs.shpWard boundary.shp

# Ward no.shpStructures.shp

S

N

EW

Chittagong Ringmain

Gas Distribution Pipe Network

GAS DISTRIBUTION LINE

Sitakunda Fault

City gate

North pahartali

Pipeline Crosses the Fault Line at Nasirabad

Vulnerable Gas Pipeline Zones in C

hittagong

Seismic Mitigation Measures

Seismic Mitigation Measures..

Retrofitting Measures for Liquefaction

a. Jet Grouting

b. Soil-cement wall

c. Compaction grout column

d. Sand Drain pile

e. Anchoring Device

Seismic Assessment of ELECTRICAL SUBSTATIONS

M.A.Aziz Stadium Substation

Mohora Substation

Patharghata Substation

Agrabad Substation

New Mooring Substation

Patenga Substation

Oxygen Substation

Electrical Distribution Poles

Defects Observed

Tilting of pole Pole too close to building

Defects Observed

Bamboo as Cross arm Corroded Transformer

At a glance…. Electrical Distribution System

Length of Electrical distribution Line=642.5 km

No. of P. C. Poles = 26,258 nos.

No. of Transformers = 2,093

12,907 poles show high vulnerability to ground shaking and Soil liquefaction.

Transformers are not vulnerable to Soil Liquefaction, but found anchorage problem.

Towers resting on hilly area, are susceptible to landslide.

Need Level-3 vulnerability Assessment.

FURTHER ASSESSMENT IS NEEDED

Distribution Poles at Jamal khan ward in dangerous condition.

Distribution Poles at Anderkilla ward are in Dangerous condition.

SEISMIC VULNERABILITY ON HOSPITAL AND CLINIC SEISMIC VULNERABILITY ON HOSPITAL AND CLINIC Buildings in CHITTAGONG CITY AreaBuildings in CHITTAGONG CITY Area……..

22 Hospitals & 22 Hospitals & Clinic Clinic Buildings Buildings coverings coverings WardsWards-- AnderkillaAnderkillaMehidibagMehidibagNasirabadNasirabad PanchlaishPanchlaish LalkhanbazarLalkhanbazar ChowakbazarChowakbazar

EERC

EARTHQUAKE VULNERABILITY ASSESSMENT OF EARTHQUAKE VULNERABILITY ASSESSMENT OF EDUCATIONAL BUILDINGS in CHITTAGONG CITY AREAEDUCATIONAL BUILDINGS in CHITTAGONG CITY AREA……

EERC

Expected damages to School Buildings.

Total No. of School Buildings surveyed in 41 City wards is 1033.

For an earthquake of magnitude 8.5 in RS at Bangladesh-Myanmar Border:

1011 school buildings will be moderately damaged, out of them 739 school buildings will be completely damaged.

WHAT TO DO FOR SCHOOL BUILDING in Bangladesh?

Earthquake Structural Assessment of Existing School Buildings

Strengthening/Retrofitting of Existing School Buildings For Future Earthquakes for an acceptable Earthquake Level.

New Building Construction Rules for Educational Buildings.

Awareness & Regular Drill Through Participatory Concept.

Rural houses at earthquake risk !Rural houses at earthquake risk !

EERC

Damage of Mud Houses during 2003 Rangamati Earthquake

Study area Study area -- Chambal, Chambal, BanshkhaliBanshkhali, Chittagong., Chittagong.

0

2000

4000

6000

8000

10000

12000

TIN

+TIN

TIN

+BA

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NO

INHABITANT

Mud House

Population Vs Types of Houses

EERC

POPULATION LIVING IN DIFFERENT TYPES OF HOUSES

MUD WALL & STRAW ROOF HOUSE- 33% - RISKY

STEEL TRUSS ROOF WITH R.C.C.COLUMN BRICK WALL HOUSE- 1%

R.C.C. COLUMN ROOF &BRICK WALL HOUSE- 2%

TIN ROOF & UNBRINED BRICK WALL HOUSE- 30%- RISKY

TIN ROOF & BRICK WALL HOUSE- 6%

TIN ROOF & MUD WALL HOUSE- 1%

TIN ROOF & TIN WALL HOUSE- 1%

TIN ROOF & BAMBOO WALL HOUSE- 6%

STRAW ROOF & BAMBOO WALL HOUSE- 20%

EERC

Strengthening technique for existing mud wall by bamboo Formulated at EERC…

Cement stabilized soil layer over plinth and portion of wall.

Strengthening of mud wall by bamboo structure

EERC

Strengthening of mud wall by jute fabrics Formulated at EERC …

A portion of mud wall, jute mat covering with the help of bamboo slice. Mud covering over the jute covering.

EERC

Shaking on mud house at EERC With & without Bamboo Reinforcement NEED FURTHER ASSESSMENT & Validation

EERC

Earthquake Vulnerability Assessment of Buildings in Chittagong City Corporation Area- Pilot Study..

RADIUSRisk Assessment Tools for Diagnosis of Urban Areas Against Seismic Disasters

United Nations Initiative Towards Earthquake Safe CitiesUN-ISDR

EERC

Study Area / Wards…

Alkaran-Firingeebazar

Andarkilla

Patharghata

South Bakalia

Bakshirhat

EERC

Surveyed 5700 Houses

Estimated consequences due to intensity VII-VIII earthquake in study areas of Chittagong city

Consequences Alkaran- Firingeebazar

Andarkilla Patharghata South Bakalia

Bakshirhat

Complete or partial collapse of residential buildings (URBM)

49% 52% 51% 54% 52%

Complete or partial collapse of educational buildings

26% 29% 27% 30% 30%

Number of people at high risk of death and serious injury

6758 3767 5302 2554 1879

EERC

NEED FURTHER ASSESSMENT

SEISMIC VULNERABILITY ASSESSMENT OF EXISTING RC BUILDINGS IN CHITTAGONG CITY IN GIS ENVIRONMENT- Pilot Study

(Istanbul Method)

Figure : Map of Purbo Maderbari Ward No.30 Chittagong City Map

GIS Maps of Purbo Madarbari Ward N0.30 (source: CDA)

Katcha Structure in Purbo Maderbari. Katcha structure in Purbo Maderbari.

Semipucca structure in Purbo Maderbari Semipucca structure in Purbo Maderbari

Percentage of different type of structures

Type of Structure

Katcha27%

Semipucca42%

Pucca31%

Katcha Semipucca Pucca

Table: Types of structure and No. of structure

Type of Structure No. of Structure

Katcha 850 (27%)

Semipucca 1329 (42%)

Reinforced Concrete (RC) 971 (31%)

Total 3150

RC Structure of GIS Building no.805 RC Structure of GIS Building no.482

240

275

176

142

96

34

5 30

50

100

150

200

250

300

No.

of s

truc

ture

1 stories 2 stories 3 stories 4 stories 5 stories 6 stories 7 stories 8/9storiesNo. of Story

No. of Story Vs No. of structure

No. of Stories 1stories

2stories

3stories

4stories

5stories

6stories

7stories

8/9stories

No. of Structure 240 275 176 142 96 34 5 3

No. of Stories vs. No. of RC Buildings

RC Structure of GIS Building no.440 RC Structure of GIS Building no.868

1 st

orie

s

2 st

orie

s

3 st

orie

s

4 st

orie

s

5 st

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6 st

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0< PS <= 6060< PS <=100

PS > 100

240

275

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50

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300

No.

of S

truc

ture

Number of Stories

Performance Score

Number of Stories Vs Performance Score

0< PS <= 60 60< PS <=100 PS > 100

Number of Stories VS Seismic Performance Score

RC Structure of GIS Building no.669 RC Structure of GIS Building no.304

RC Structure of GIS Building no.967 RC Structure of GIS Building no.199

RC Structure of GIS Building no.645 RC Structure of GIS Building no.679

RC Structure of GIS Building no.604 RC Structure of GIS Building no.611

RC Structure of GIS Building no.949 RC Structure of GIS Building no.611

Performance Group of RC Buildings

42

80

0

0

10

20

30

40

50

60

70

80

NO

. of B

UIL

DIN

GS

LOW RISK GROUP MODERATE RISK GROUP HIGH RISK GROUPPERFORMANCE GROUP

PERFORMANCE GROUP CLASSIFICATION

LOW RISK GROUP MODERATE RISK GROUP HIGH RISK GROUP

GIS Building Color Code Map of Purbo Madarbari Ward No-30

NEED

FUR

THER

ASSESSM

ENT

Concrete Moment Frame with Unreinforced Masonry Walls

Concrete Slab-Column Frame

Buildings Vulnerable to Earthquake

Buildings Vulnerable toEarthquake

NEED TO BE INVESTIGATED

NEED TO BE INVESTIGATED

Lightly Reinforced Concrete Frame (Non-Engineered RC )

NEED TO BE INVESTIGATED

Unreinforced Masonry with Concrete Roof & Floor (BC)

BC - Brick in cement mortar masonry with concrete floor are masonry buildings with concrete slab and structural masonry wall and no confined reinforced concrete column.

BC

NEED TO BE INVESTIGATED

Unreinforced Masonry with Flexible Roof (BF,BL)

BF - Brick in cement mortar masonry with flexible roof are similar to the one with concrete floor. However, due to lacking of rigid diaphragm that confines the masonry wall, its seismic behavior is considerer poorer.

BF

NEED TO BE INVESTIGATED

Tin Shed (TS) Bamboo (BA)

TS- Tin shed is minimum standard structure constructed by tin shed for wall and roof.

BA- Bamboo refers to building which use bamboo as structural component to resist both the lateral and gravity loads.

Houses Not Vulnerable to Earthquakes

Concrete moment frame with unreinforced masonry infills

Percentage of total building population in each occupancy

Data from 8,337 buildings in Dhaka

Residential + Commercial

Correlation between occupancy class & structural type

Seismic Building Vulnerability Factors

Percentage of total building population in each occupancy

Percentage of total building population in each occupancy

1.5 m

Large opening

Soft Story Problems!

Soft Story Problem

Soil Liquefaction Failure during Earthquake

Ground Floor Parking-Soft Story Failure

Flat Plate Slab Building (without beam) in Bangladesh

Flat Plate Slab Buildings Collapsed during Earthquake

Collapsed Flat Plate Slab Buildings During Earthquake

Seismic Capacity of Flat Plate Buildings in BangladeshNEED TO BE VALIDATED BY EXPERIMENTAL INVESTIGATION

Expected damage scenario For Chittagong due to earthquakes! Source: Magnitude 8.5 in RS at Bangladesh-Myanmar Border

Buildings: Total no. of RC buildings =1,82,000 out of which 1,68,150 nos. will be damaged beyond repair.

Hospitals: Total no. of hospitals =162 having 21,664 beds out of which only 923 beds will be available for use.

Police stations: Total no. of police stations =11 out of which 10 will be completely damaged.

Fire stations: Total no. of fire stations = 12 out of which 8 will be completely damaged.

Water line: 407 breakages in the 542Km water line.

Gas line: 125 breakages in the 217 Km gas line.

Electric line: 28,407 no. of electric poles will be moderately damaged.

Debris generation: 17MTons and need 6,80,000 Truck loads to clear.

Death: at night 2pm: 1,37000 and at daytime 2pm 73,000

Critical Infrastructure Damage to Economical Collapse of Bangladesh!!

Petroleum Industries

Only Sea Port (Chittagong) & its Facilities

Air Port Facilities

Power Generation & Distribution System

Bridges

NEED IMMEDIATE ATTENTION BY THE AUTHORITY

Life Lines Damage To Death & Economical Collapse of Bangladesh !!

Power Plant, Distribution Network & Sub Stations

Gas Supply & Distribution Systems

Water Supply & Distribution Systems

NEED IMMEDIATE ATTENTION BY THE AUTHORITY

Seismic Risk & Its Components

Seismic Hazard

Seismic Vulnerability

Example of Seismic Vulnerability

Soft Story

Pounding

Vertical Irregularity

Disaster Risk Reduction Process

RISK REDUCTION: Shifting REACTIVE Approach to PRO-ACTIVE Approach

DISASTER Risk Reduction Elements

Seismic Risk Reduction

REACTIVE

Risk Reduction

Risk Reduction

Example of Engineering Measure

Risk Reduction

What to Do Now ?

Seismic vulnerability Assessment of critical installations along the river belt of Karnaphulli and adopt the remedial measures without any further delay.

Seismic structural strength assessment of existing buildings.

Strengthening of existing foundation system and superstructures of Critical structures.

Incorporation of liquefaction potential criteria in the structural design process for structures in the planning stage.

Awareness of the policy makers for the formulation of Bangladesh Earthquake Master Plan.

EERC

TO FORMULATE Seismic Risk TO FORMULATE Seismic Risk Reduction StrategiesReduction Strategies……………………

WE NEED TO PERFORM PROFESSIONALLY-1. Building Vulnerability Assessment of Buildings through

Experimental Validation

2. Seismic Vulnerability Assessment of CHITTAGONG SEA PORT

3. Seismic Vulnerability Assessment of Gas & Petroleum Refineries

4. Seismic Vulnerability Assessment of Life Lines

FINALLY NEED FINALLY NEED BANGLADESH EARTHQUAKE MASTERPLANBANGLADESH EARTHQUAKE MASTERPLAN

For Earthquake Safe BangladeshFor Earthquake Safe Bangladesh

Community ParticipatoryCommunity Participatory--Based Based Bangladesh Earthquake Master PlanBangladesh Earthquake Master Plan

Village Level

Union Level

Upzilla Level

Ward Level

District Level

National Level

It Is Not Nature But Community Is Responsible For Disaster !!!

An Efficient Governance is Essential to Build a Safer Community…..

Looking For Looking For Earthquake Earthquake

Safer Safer CommunitiesCommunities……

BangladeshBangladesh

VielenVielen Dank Dank fuerfuer IhreIhre AufmerksamkeitAufmerksamkeit