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					May 12, 2008 Sichuan, China
Earthquake Reconnaissance
       Zhenming Wang
  Kentucky Geological Survey
          228 MMRB
    University of Kentucky
     Lexington, KY 40506
      zmwang@uky.edu

   KGS Brown Bag Seminar
       July 10, 2008
           Acknowledgement

• Mr. Furen Xie (Deputy Director, Institute of
  Crustal Dynamics, CEA)
• Dr. Lanmin Wang (Director, Lanzhou
  Institute of Seismology, CEA)
• Mr. Yi Du (Institute of Crustal Dynamics,
  CEA) – in Sichuan
• Dr. Zijian Wu (Lanzhou Institute of
  Seismology, CEA) – in Gansu
                 Outline
• General Earthquake Information

• Some Observations
  – Chengdu
  – Dujiangyan
  – Xiaoyudong
  – Hanwang
  – Pintong

• Lesson Learned
 Magnitude: 8.0 (7.9 USGS)
 Fault Rupture: ~300 km x 30 km
 Surface Displacement: 5m (v), 4.8m (h)
 Largest Recorded PGA: 0.65g
 Death: ~70,000
 Missing: ~20,000
 Injured: ~380,000
 Economic loss: ~$450B




The map is from CEA website (http://ww.cea.gov.cn:99/)
The Felt Areas of the Wenchuan M8.0 Earthquake




                                     Felt Areas

                   Epicenter
                                   1,000 miles




   Strongly Felt
   Areas
 Peak Ground Acceleration (E-W component) of Wenchuan M8.0 Earthquake
                    CEA website (http://ww.cea.gov.cn:99/, no contour value was given)




                                              0.08g


                                                                         0.14g

                                                                 0.16g
                                                                                 0.12g
                                                          0.18g
                                                         0.20g
                    0.65g                             0.30g                        0.10g




                                                                                           0.08g




* The contour values were estimated and may not be accurate.
                               Ce
          Fr                     nt
             on                    ra
               ta                    l fa
                  l   fa                    ul
                         ult                   t




Chengdu
        Apartment building
                                      City Center



         Chengdu Airport




Fault distance: 50~60 km, no damage
                                      Yulin Hotel
Dujiangyan
                         Ce
    Fr                     nt
       on                    ra
         ta                    l fa
            l   fa                    ul
                   ult                   t
                                                                                 Tourist City




                                                      Dujiangyan

                                                                   90% buildings damaged
                                                                   102 buildings collapsed




Dujiangyan-Irrigation system, built 2,000 years ago
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
                                                        Juyuan MS survivor
     Luo Yu Zheng is crying for the losses of her son      Guo Tao (16)
     (Tao Liang killed at Juyuan MS) and house.




Results from the natural + manmade disasters
                                                          Juyuan MS victim
                                                            Tao Liang (16)
Dangerous road
Damaged bridge




       Lateral spreading
Houses with minor damage




    Collapsed house



                           “the best house – good construction quality”


High Plateau Village
                         Ce




   Xiaoyudong
Fr                         nt
   on                        ra
     ta                        l fa
        l       fa                    ul
                   ult                   t
Collapsed and severe damaged houses in this area
         upture
Surface r
                  Bridge collapsed




                                 Rupture
                                   House with some damage




                         Ru
                           ptu
                              re




This may be the reason
                     Ce
Fr                     nt
   on                    ra
     ta                    l fa
        l   fa                      ul
               ult                     t
                          Hanwang
Clock stopped at 2:28pm on May 12, 2008
Collapsed school buildings
Collapsed school buildings
Collapsed school buildings
Cut though levy

                                             Uplift
                                Water fall




                  Frontal fault rupture
Family lunch on top of ruptured fault




                  Fault rupture



                                        Minor damage
                     Ce
Fr                     nt
   on                    ra
     ta                    l fa
        l   fa                    ul
               ult                   t
                                         Pintong
                        Pintong MS




Central Fault rupture




                          Pintong MS




                                              e
                                       R uptur
100+ students were killed




Collapsed school buildings
                           50+students were killed




Fault
                      Pintong ES
                40+ student were killed




        Fault
                              Massive landslide




less damage
(lower plate)                                     More damage
                                                  (upper plate)




                       ture
                   rup
                    lt
                Fau
Fault rupture

        ~50m    No damage to this house
                (about 50 m from the rupture)
Buried house   Large landslide




                      House
60+ people were buried




                           Fault scarp




           Buried houses




                                         Fau
                                             lt r   uptu
                                                        re
    Lesson 1 – Earthquake Science
                                                                                              Primary Hazard
                                                                                              1. Ground Motion
                                                                                              2. Fault Rupture

                                    0.20g   0.18g
                            0.30g
       0.65g
                                              0.16g


                                               0.14g

                                                                                              PGA Attenuation Curve for M8.0
                                                0.12g                            1.E+00


                                                                                 1.E-01




                                                              Acceleration (g)
                                                                                 1.E-02
                                                      0.10g
                                                                                 1.E-03


                                                                                 1.E-04
                                                                                                CEUS-A08

                                                                                 1.E-05
                                                                                                WUS-BA07
                                                                                                Wenchuan

                                                                                 1.E-06
                                                                                          1            10                      100   1000

                                                                                                           Rupture Distance (km)




Earthquake science is the base for seismic hazard assessment and mitigation
      Lesson 2 – Design Ground Motion
                                                           Building damage
  Recurrence interval: 2,000 – 5,000 years                 1. Under design
                                                           2. Quality of construction
                                          0.18g
                                                                              Design PGA
                                  0.20g                                    (10% PE in 50 yrs)
      0.65g
                          0.30g

                                                   0.16g

                                                                        0.20g
                                                  0.14g

                                                                           0.15g
                                             0.12g


                                                                                    0.05g


                             0.10g
                                                                0.10g

How about PGA with 5 and 2% PE in 50 yrs.?
Lesson 3 – Induced (secondary) hazards
                       Secondary Hazard
                       1. Landslide/Rock fall
                       2. Ground Motion Amp.
                       3. Liquefaction (reported)




                                 Town of Hanwang




                             100% buildings damaged
        Lesson 4 – Mitigation Works




Not necessary expensive
Not design for 0.6g PGA or larger
                                    Ru
                                    p tu
                                         re
Thank you!

				
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