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May 12, 2008 Sichuan, China May 12, 2008 Sichuan, China Earthquake ReconnaissanceEarthquake Reconnaissance
Zhenming WangZhenming WangKentucky Geological SurveyKentucky Geological Survey
228 MMRB228 MMRBUniversity of KentuckyUniversity of KentuckyLexington, KY 40506Lexington, KY [email protected]@uky.edu
July 2008July 2008
AcknowledgementAcknowledgement
• Mr. Furen Xie (Deputy Director, Institute of Crustal Dynamics, CEA)
• Dr. Lanmin Wang (Director, LanzhouInstitute of Seismology, CEA)
• Mr. Yi Du (Institute of Crustal Dynamics, CEA) – in Sichuan
• Dr. Zijian Wu (Lanzhou Institute of Seismology, CEA) – in Gansu
OutlineOutline• General Earthquake Information
• Some Observations– Chengdu– Dujiangyan– Xiaoyudong– Hanwang– Pintong
• Lesson Learned
Magnitude: 8.0 (7.9 USGS)Fault Rupture: ~300 km x 30 kmSurface Displacement: 5m (v), 4.8m (h)Largest Recorded PGA: 0.65gDeath: ~70,000Missing: ~20,000Injured: ~380,000Economic loss: >US$120B
The map is from CEA website (http://ww.cea.gov.cn:99/)
The Felt Areas of the The Felt Areas of the WenchuanWenchuan M8.0 EarthquakeM8.0 Earthquake
Felt Areas
Strongly Felt Areas
Epicenter1,000 miles
0.30g
0.20g
0.18g
0.65g
0.08g
0.12g
0.14g
0.16g
0.08g
Peak Ground Acceleration (E-W component) of Wenchuan M8.0 Earthquake
* The contour values were estimated and may not be accurate.
CEA website (http://ww.cea.gov.cn:99/, no contour value was given)
0.10g
Centra
l fault
Fron
tal fa
ult
Chengdu
Fault distance: 50~60 km, no damage
Chengdu Airport
City Center
Yulin Hotel
Apartment building
Centra
l fault
Fron
tal fa
ult
Dujiangyan
90% buildings damaged102 buildings collapsed
Tourist City
Dujiangyan-Irrigation system, built 2,000 years ago
Dujiangyan
Collapsed building in Dujiangyan
Collapsed building in Dujiangyan
Damaged police station (new) in Dujiangyan
Damaged new hotel in Dujiangyan
Juyuan Middle School ( 300+ students were killed)
Zhipingpu Dam, built in 2005
Water level before earthquake
Damaged house
Results from the natural + manmade disasters Juyuan MS victimTao Liang (16)
Juyuan MS survivorGuo Tao (16)Luo Yu Zheng is crying for the losses of her son
(Tao Liang killed at Juyuan MS) and house.
Dangerous road
Lateral spreading
Damaged bridge
“the best house – good construction quality”
High Plateau Village
Collapsed house
Houses with minor damage
Centra
l fault
Fron
tal fa
ultXiaoyudong
Collapsed and severe damaged houses in this area
Surfa
ce ru
ptur
eBridge collapsed
Rupture
Rupture
House with some damage
This may be the reason
Centra
l fault
Fron
tal fa
ult
Hanwang
Clock stopped at 2:28pm on May 12, 2008
Collapsed school buildings
Collapsed school buildings
Collapsed school buildings
Water fallUplift
Cut though levee
Frontal fault rupture
Family lunch on top of ruptured fault
Fault rupture
Minor damage
Centra
l fault
Fron
tal fa
ult
Pintong
Central Fault rupture
Pintong MS
Pintong MS
Rupture
100+ students were killed
Collapsed school buildings
50+students were killed
Pintong ES40+ student were killed
Fault
Fault
Foot wall
Hanging wall
Massive landslide
Faul
t rup
ture
less damage(foot wall) More damage
(hanging wall)
~50m
Fault rupture
No damage to this house(about 50 m from the rupture)
Buried house
House
Large landslide
Fault scarp
60+ people were buried
Fault rupture
Buried houses
Lesson 1 Lesson 1 –– Earthquake ScienceEarthquake Science
0.12g
0.14g
0.16g
0.18g
0.65g 0.30g
0.10g
Primary Hazard 1. Ground Motion2. Fault Rupture
0.20g
Earthquake science is the base for seismic hazard assessment and mitigation
PGA Attenuation Curve for M8.0
1.E-06
1.E-05
1.E-04
1.E-03
1.E-02
1.E-01
1.E+00
1 10 100 1000
Rupture Distance (km)Ac
cele
ratio
n (g
)
CEUS-A08WUS-BA07Wenchuan
Lesson 2 Lesson 2 –– Design Ground MotionDesign Ground Motion
0.10g
0.15g
0.20g
0.05g
0.12g
0.14g
0.16g
0.18g
0.20g0.65g
Design PGA(10% PE in 50 yrs)
0.10g
Building damage1. Under design2. Quality of construction
0.30g
Recurrence interval: 2,000 – 5,000 years
How about PGA with 5 and 2% PE in 50 yrs.?
Lesson 3 Lesson 3 –– Induced (secondary) hazardsInduced (secondary) hazardsSecondary Hazard 1. Landslide/Rock fall2. Ground Motion Amp.3. Liquefaction (reported)
Town of Hanwang
100% buildings damaged
Lesson 4 Lesson 4 –– Mitigation WorksMitigation Works
Rupture
Not necessary expensiveNot design for 0.6g PGA or larger
“Best Story”Shan Zhao Middle School
All evacuated in 2 minutes after EQ 2,200 students with no single injury
Built in 1980’s (RMB170,000)Retrofit (RMB400,000)
School Principal: 叶志平 (Ye Zhi Ping)
Thank you!