earthquake risk in bangladesh
TRANSCRIPT
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
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
China Earthquake-2008 Lesson Learnt From Real-time Earthquake Experiments!!!
Magnitude was 7.9 in RS
Damage to Transmission Line and Electric Sub-station due to Liquefaction during 1999-Taiwan Earthquake
Andam
an Earthquake of 7.6M-2009
Tectonic Plates near Bangladesh
Animation of Tectonic plate movement from Prof.Akhter of Dhaka University
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
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
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
Chittagong Hill Tract Hydro Power Station
Seismic Safety Assessment of Hydro Power Station is needed
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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
OA
D
RAILWAY ROAD
COU RT ROAD
PAT
ENGA
RO
AD
PC ROAD
FROM
COM
ILLA BAKHRABAD
HATHAZARI
CTG. CANT.
SITAKUNDA
BA
Y
OF
B
E
NG
AL
AIRPORT
KA
R
NA
FU
LI
R
IV
E
R
Nasirabad Zone
Kalurghat Zone
Port conn ecti ng road
Bakalia
Double m
ooring r o
ad
CU
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
Retrofitting Measures for Liquefaction
a. Jet Grouting
b. Soil-cement wall
c. Compaction grout column
d. Sand Drain pile
e. Anchoring Device
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
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
MBO
O
STRA
W+B
AM
BOO
STRA
W+M
UD
TIN
+R.C
.C.
TIN
+TIM
BER
R.C.
C.
TIN
+BRI
CK
TIN
+UN
.BRI
CK
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)
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
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
1 st
orie
s
2 st
orie
s
3 st
orie
s
4 st
orie
s
5 st
orie
s
6 st
orie
s
7 st
orie
s
8/9s
torie
s
0< PS <= 6060< PS <=100
PS > 100
240
275
133
1 0 0 0 0
0 0
43
142
171 0 0
0 0 0 0
79
34
53
0
50
100
150
200
250
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
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
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
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
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
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…..