Microsoft PowerPoint - 42 Reserching Project_JNES

Document Sample
Microsoft PowerPoint - 42 Reserching Project_JNES Powered By Docstoc
					Current state of researching project for the 2007
Niigata-ken Chuetsu-Oki earthquake and strong
     ground motions due to this earthquake


                  January 29,2008



         Japan Nuclear Energy Safety Organization




                                                    1
           〔 Content of this presentation 〕
Ⅰ. Review items to secure seismic safety of Kashiwazaki
   - Kariwa Nuclear Power Plant (hereafter KKNPP) .
  (NISA documents)
Ⅱ. Observed Strong ground motions in KKNPP and
   characteristics of the source area and the site.
Ⅲ.Key points for finding out the causing factors of
  unexpectedly strong ground motions exceeding the
  design level.
Ⅳ.The method for analyzing the earthquake and strong
  ground motion.
Ⅴ.Published information related with this researching
  project.
                                                          2
Review items to secure seismic safety of Kashiwazaki – Kariwa
Nuclear Power Plant (hereafter KKNPP) .        (NISA documents)




                                             Report Contents of JNES




                                                                       3
Ⅱ. Observed Strong ground motions in KKNPP and characteristics of the source area and the site
 (1) Characteristics of observed strong ground motions in the KKNPP
① Very large ground motions observed in ② Large amplitude pulse in latter of              ③ Amplitude of pulses in latter half of waveform at
   KKNPP locating close to source area.               time history waveform at UNIT K1     UNIT K5 side are smaller than that at UNIT K1 side.
a) Relationship between attenuation relation          side. ⇒ Large amplitude of response ④ Distinct pulses in anterior and latter half of
  and observed ones                                   spectra and strong ground motion      waveforms are appeared at all units.
                  Surface station near UNIT 5:1223Gal
                                                      exceeding largely the design level.   Rather obscurely pulses are seem in middle part.
                     Surface station near UNIT 1:890Gal
                                                                  b) Characteristics of observed acceleration waveforms on the basement of all units (EW component)
                                                     1000
                                                                   680Gal                       K1         606Gal K2                           K3                 K4                      K7                             K6                       K5
                                                                                                                                          384Gal                 485Gal               366Gal                      322Gal
                                                       500                                                                                                                                                                                318Gal
       Fault plain with
       the NW dip                                         0

          K-Net
          Shi and Midrikawa                           -500                                                                                                                                                                             * 442Gal
                                                              0     5       10                    15 0     5      10    15 0          5     10       15 0   5   10   15     0     5      10      15 0         5     10        15 0    5      10        15

                                                                                                c) Response Spectra using the record                                                K1~K4                                     K7~K5
                              (http://www.kojiro-irikura.jp/)
                                                                                                   on basement in UNIT K1
                                                                                                2000

  (2) Characteristics of source area                                                                                                       Spectral acceleration




                                                                        Acceleration Response
                                                                                                               Observed                         decreases                                                                            Under ground station
      and the KKNPP site                                                                        1500           record                        according to the


                                                                          加速度応答スペクトル
                                                                                                                                                                                                                                     near UNIT K6




                                                                            Spectrum (s)
                                                                                                                                            amplitude of pulse                                            1km
   ・Reactor buildings are deeply embedded                                                       1000
                                                                                                                                                                                         Surface station near UNIT K1
                                                                                                                                                                                                                                 Under ground station
    and installed on soft rock .                                                                                                                                                                                                  near UNIT K5
   ・Front face of soft rock stratum have gentle                                                  500
                                                                                                                                                                                                        Surface station near UNIT K5
                                                                                                                                                                          Under ground station near UNIT K1
     slope by fold structure.                                                                          In the case of half pulse                                            d) Location of                    Service hole
   ・Stratum estimating as exposed-bedrock                                                                     of latter half                                                    each unit
                                                                                                   0
     (Vs=700m/s) is deeply located.                                                                 0.01         0.10
                                                                                                                    Period (s)
                                                                                                                     周期(秒)
                                                                                                                               1.00              10.00




Ⅲ. Key points for finding out causing factor of strong                                                                                            response of
                                                                                                                                                                                                                               Vibration
                                                                                                                                                                                                                              focusing?
                                                                                                                                                                                           sand・
                                                                                                                                                                                           sand・Fill soil
   ground motions exceeding the design level.                                                                                                soil-
                                                                                                                                             soil-structure system
                                                                                                                                                                                                                         Soft rock
① Factors causing severe intensity records on basement                                                      Assumed cause
  exceeding the design level.                                                                                  of large                      Effects of site condition
  ⇒ Finding out factors causing large amplitude pulse                                                       amplitude pulse
    (Especially UNIT K1 side)                                                                                                             Effects of propagation path
                                                                                                                                                                                                                         Hard rock
② The reason why each unit have different observed                                                                                              (ground structure)
  records.
   ⇒ Finding out factors causing the pulses with                                                                                                                                                                              Cause of large
                                                                                                                                      Effects of source characteristics                                                       amplitude pulse
     different level for each unit.                                                                                                                                                   Source fault model
                                                                                                                                                                                                                                                            4
Ⅳ. Method for analyzing the earthquake and strong ground motion (1/3)
                                                                                       Soil-building
■ Key point for analyzing                                                              dynamic interaction           Observed record
                                                                                                                                                  Sand

①Finding out cause of large amplitude pulse(Especially UNIT K1)                             Fill soil                 Fill soil          Yasuda stratum


②Finding out cause of the different pulse level between UNIT K1            Nisiyama
                                                                                                                            Nisiyama stratum

 side and UNIT K5 side                                                     stratum       〔Approach1〕                 Exposed
                                                                                       Estimating bedrock
                                                                                       motions using                 Bedrock*1
■ Procedure of analyzing                                                               observed records
①Approach1:Estimating bedrock motions from observed records                                                          Seismic
                                                                                      Characteristics of             bedrock
⇒Estimating various bedrock motions* by using main and after                          Propagation path
  shocks records and studies characteristics of bedrock motions.
⇒Studying the difference in characteristics of strong motions             Characters of
                                                                                                                                  〔Approach2〕
                                                                                                                            Estimating bedrock
  on basement and bedrock motions.                                        source                                            motions using
                                                                                                        Aftershock          source fault model
 〔Points to be checked〕
 ・Checking relations between amplification by local site effects
                                                                         Source of main shock
   or soil-building dynamic interaction and large amplitude pulse.
                                                                          Studies causing factors of large amplitude
 ・Checking the difference of above relations for all units.
                                                                          pulses using estimated bedrock motions*2 by
 〔Considered Points when estimating bedrock motions〕                      approach ①,②
 ・Soil nonlinearities including soft rock, irregularities of bedrock.      ・Breaking down occurrence and amplification
                                                                            process of pulse between source to units.
Approach2:Estimating bedrock motions using fault model
                                                                             -Analysis of aftershocks: effects of
⇒Estimating various bedrock motions* by using main and after                   propagation path, vibration amplification
  shocks records and studies characteristics of bedrock motions.               between bedrock to exposed bedrock.
 〔Points to be checked〕                                                      ‐Source characteristics of main shock,
 ・Checking relations between directivity of source,                            Effect of soil nonlinearities and soil-
  topographic irregularities or vibration amplification on site               building dynamic interaction.
  and large amplitude pulse.                                               ・Estimating the difference of amplitude and
                                                                             characteristics of motions according to
 ・Checking the difference of above relations for all reactors.               location and depth.
 〔Considered Points when estimating bedrock motions〕                      *1 Exposed bedrock : Base strutum which was formed in
 ・Validity of estimated source model and source parameters.                  general in the Tertiary or earlier era (Vs=700m/s) and
                                                                             at where design earthquake is defined.
 ・ irregularities of bedrock, soil nonlinearities including soft rock.    *2 bedrock motion : exposed bedrock and bedrock motion                          5
Ⅳ. Method for analyzing the earthquake and strong ground motion (2/3)
   ① Approach1:Outline of the method estimating bedrock motions using observed records in the
              KKNPP(UNIT K1 side・UNIT K5 side・service hall)
  ■The method estimating bedrock motions using                       ■The method estimating bedrock motions using observed records on the basement
   observed records at service hall (for example)                                                     in units (for example)
                                                                   ●Estimation of exposed bedrock motion ● Estimation of exposed bedrock motion
           P、S-wave velocity(m/s)
                                                                    considering of soil-structure interaction      considering of topographic irregularities
 (Depth)                                                            (as shown in example)                          (as shown in example)
                                                                       ⇒Analysis using numerical model                 ⇒FEM analysis using multidimensional
                                                                         for simulation of seismic response              structure-soil model
 Sand                                       Observed record
                                            at surface station                                                           Observed motion          Sand                       Observed motion
 Sand.                 Water level           near UNIT K1                                                                on basement         Fill soil                       on basement
 Gravel

                                              Comprehending




                                                                    Side viscous boundary
                                                                                                                                        Yasuda stratum
Yasuda                                       soil nonlinearities
stratum                                                                                                                             Estimation of exposed                 Manmade rock
                                                                                                                      Data of          bedrock motion
                                                                                                                      soil and     considering topographic             Nisiyama stratum
                                       Optimization of analytical                                                                        irregularities
                                      model using observed                                                           structure
                                      records
                                      ・Relations between                                                                         Ex..)2-D FEM model for UNIT K7
                                       stiffness and damping                                                                      (Installation license application)    Siiya stratum
                                       of soil to strain
Nisiyama
stratum
                                                G-γ                                                                                     Base viscous boundary
                                                                                            Base viscous boundary

                                          h-γ                                                       Estimated exposed            comparison Estimated exposed
                                                                                                    bedrock motion                          bedrock motion
                                       ・Scatter damping
                                        ⇒frequency-dependent
                                         (h=h0f- -α)                              Identification of soil property                 Comparison of bedrock motions estimated
                                                                                  and scatter damping using                       from UNIT K1, UNITK7 and service hole
                                                                                  observed underground motions
                                            One dimensional
                                             One dimensional
                                            wave propagation
                                            wave propagation
                                                                                  of aftershocks at UNIT K1 and K5
                                                                                                                                                                                          K7~K5
                           Observed         theory
                                             theory
                        E waveform of
                              main shock                                                    S.H Comprehension of                                           K1~K4
                                (E+F)
                                                                                                topographic irregularities                                                 Axis of an anticline
                                       Estimation of incident
                                       wave to bedrock
                                       motion of main shock
                                                                                                                                                     Service hall
                                                                                                                                                        (S.H)          Axis of a syncline
                                                                                                                                                                                                  6
Ⅳ. Method for analyzing the earthquake and strong ground motion (3/3)
     ②Approach2:Outline of the method estimating bedrock motions using source model
                                                                                                             ・Data of geological survey                       ■Survey of fault, structure etc.
                                                                                                                 in the KKNPP etc.      ・Velocity structure of ・Exploration of source
                                                                                                                                         deep underground of   ・Exploration of structure with
                                                                                                                                            Chuetu area*1       detailed array network
                                                                                                 Sand
                                                                                                               〔Structure model              (JNES.2005)       ・Boring survey for deep
                   Fill soil                           Fill soil                     Yasuda stratum                                                             underground etc.
                                                                                                                       for shallow underground〕
                                                             Nisiyama stratum
 Nisiyama                           Site effect                                                               〔Structure model for deep underground〕
 stratum
                                                       Exposed bedrock

                                                      Seismic
                                                      bedrock
              Effect of wave
               propagation


   Source charactertcs
                                                         Estimation of                                                                                                            ■Estimated source information
                                                        bedrock motion                                                                                                             from simulation of tectonic
 〔 Source fault model 〕                               using source model                                                                                                           landform・strong ground
                                                      ・Hybrid method etc.                                              AIST AFRC HP:「Relation 3-D structure model and              motion・tunami etc.
                                                                                                                               source of Chuetu earthquake )

 Set source model(Considering proposed characterized source models                                                                                            Review submarine active faults by
                   by several research institutes)                                                                                                              submarine geological survey
                                                                                                                                                            Submarine fault  Active fault・active fold
 Source model                             Top depth
                                                                                                     Latitude:37.495°
                                                                                                     Longitude:138.653°
 (for example)                               2.0km                                                   Strike:220°
                                                              Wi
                                                                dt
                                                                  h1
                                                                    4k
                                                                      m                                                                                                         Main
                               Latitude:37.409°                                                      Top depth 4.0km
                                                                                   km




                                                                                                                                                                                shock
                                                                                 12




                               Longitude:138.460°
                                                                                 h




                               Strike:40°
                                                                               dt




                                                                                                                                                                   Depth (km)
                                                                             Wi



                                                                                         Len
                                                                   Le n




                                                                                             gth
                                                                       gth




                                                                                                 2
                                                                       10k




                                                                                               7km
                                                                             m




                                                                                                        (Geographical Survey Institute)                                         (ERI of University of Tokyo)
            (*1:Study of probabilistic method concerning earthquake = Evaluation of ground motion characteristics based on identification of deeper structure = JNES/SAE05-48, 2005.12)                        7
 Ⅴ.Published information related with this researching project (1/6)
    ① Geological and topographic data in the KKNPP
      (as shown in example)                                                                              Axis of syncline                                     Axis of anticline

     Tokyo Electric Power Company (TEPCO) : Application for establishment                       South                                                                                                               North
     permit of Kasiwazaki-kariwa nuclear power plant (UNIT 6, 7),                                                           K1 K2 K3       K4                                               K7 K6 K5
                                                                                                                                                                                                       Quaternary
     May 1988, (patial revision at January 1990)                                                                                                               Quaternary
                                                                                                  Quaternary                                                                                                   Quaternary
                                                                                                                                                                deposits
                                          Ⅰ                                                        deposits
                                                                     Ⅲ
                      Ⅱ                                                                        Haizume formation



                                                                     K7~K5                                                             Nisiyama formation

                                                                                   Ⅰ’
                                              K1~K4
                                                                         Axis of anticline                                                                                           Siiya formation

                                                                                                                                                                                                       Each level indicates
                                                                                                                                                                                                        surface of exposed
                                                                                                                                                                                                             bedrock


                                                                Ⅱ’
                                     Service hall                                       〔Ⅰ‐Ⅰ’cross-section〕
                                                         Ⅲ’   Axis of syncline
                                                                                                               K7~K5
                                                K1~K4
                                                                                                               Ⅲ‐Ⅲ’
                      Ⅰ                                                                                                                                                                                                     Ⅰ’Altitude



Altitude                                                                                                                                                                                               Histogram legend
  (m)                                                                                                                                                       Geological legend                                   Silt Clay
                                                                                                                                                             Fill soil               Mudstone                    Sand
                                                                                                                                                              Sand                   Mudstone Nisiyama
                                                                                                                                                                                              Formation          Gravel
                                                                                                                                                              Sand                   Mudstone                  Mudstone
                                                                                                                      Data from boring survey               Silt Clay                 Rock     Siiya
                                                                                                                                                                                     Mudstone Formation        Mudstone
                                                                                                                                                             Sand         Yasuda                               Mudstone
                                                                                                                                                                         Formation
                                                                                                                                                                                                                 Rock
                                                                                                                                                             Gravel                                            Mudstone
                                                                                                                                                                                                                Gravel
                                                                                                                                                                                                                Rock
                           Service hall                                              〔Ⅲ‐Ⅲ’cross-section〕
                                                                                                                                                K7~K5
                                                                                                         Axis of anticline
                          Ⅲ’                                                                                                                                                                           Ⅲ




           Altitude                                                                                                                                                                                                           Altitude
             (m)                                                                                                                                                                                                                (m)


                                      Axis of syncline



                                                                                                                                                                                                                                      8
Ⅴ.Published information related with this researching project (2/6)
 ② Structure model for deep underground                             37.6
                                                                                                                                                    37.6




                                                                                                                                                                     ke
                                                                                 qu -oki
 of Chuetu-region (as shown in example)




                                                                                                                                                             rth oki
                                                                                      e




                                                                                                                                                                   ka
                                                                                                                                                                                                                    Depth(m)




                                                                                   kak




                                                                                                                                                           ea uetu-
                                                                           ea uetu




                                                                                                                                                                qu
                                                                                                                                            8000    37.5
 Japan Nuclear Energy Safety Organization :Study of probabilistic   37.5
                                                                                                                                            7000
                                                                                                                                                                                                                         8000




                                                                             rth
                                                                                                                                                                                                                         7000




                                                                                                                                                       Ch
                                                                              h
 method concerning earthquake = Evaluation of ground motion                                                                                 6500




                                                                       C
                                                                                                                                            6000                                                                         6500
 characteristics based on identification of deep underground                                                                                5500                                                                         6000

 structure = JNES/SAE05-48, 2005.12)
                                                                    37.4                           KKNPP                                    5000
                                                                                                                                                    37.4                          KKNPP                                  5500
                                                                                                                                            4500                                                                         5000
                                                                                                                                            4000                                                                         4500
                                                                                                                                            3500                                                                         4000
                                                                    37.3                                                                    3000    37.3                                                                 3500

              地質時代                    新潟油田地域
                                     Nigata oil field                                                                                       2500                                                                         3000
            Geological age                                                                                                                  2000                                                                         2500
                                     (本報告の区分)
                                   (Sorting of this report)                                                                                 1500                                                                         2000
                                                                    37.2                                                                    1000    37.2                                                                 1500
                                                                                                                                            500
                    完新世
                   Holocene                                                                                                                 400
                                                                                                                                                                                                                         1000
                                                                                                                                                                                                                         500
                                          Alluvium                                                                                          300                                                                          400
                                          沖積層                       37.1                                                                    200                                                                          300
                                      Terrace deposit
                                       段丘堆積物
                                                                                                                                                    37.1
                           後期
                          Late
                                                                                                                                            100
                                                                                                                                            50
                                                                                                                                                                                                                         200
                                                                                                                                                                                                                         100
        Quar-
       第四紀                                                                                                                                  0
                                                                                                                                                                                                  Upper                  50
       ternary                                                       37
                                                                                                                    Nisiyama                         37                                                                  0
                 更新世 中期
                 Pleist- Middle                                                                                                                                                                   Teradomari
                 ocene               魚沼層群
                                Uonuma Formation                                                                    Formation
                                      灰爪層
                                Haizume Formation                   36.9
                                                                                                                                                    36.9
                                                                                                                                                                                                  Formation
                          前期
                         Early                                         138.4     138.5     138.6   138.7    138.8    138.9   139   139.1
                                                                                                                                                       138.4     138.5    138.6   138.7   138.8    138.9   139   139.1


                                   Nisiyama Formation
                                         西山層                        37.6                                                                           37.6




                                                                                                                                                                      ke
                                                                                                                                                                    ka i
                                                                                                                                                              rth -ok
                            後期
                           Late


                                                                                qu ki
                                                                                     e
                                                                             rth -o
                                                                                  kak
                 Plio-                                                                                                                 Depth(m)




                                                                                                                                                           e a u etu
                                                                                                                                                                                                                    Depth(m)
                 鮮新世
                                                                           ea uetu




                                                                                                                                                                 qu
                 cene                                               37.5
                                                                                                                                            8000   37.5
                                                                                                                                                                                                                         8000
                           前期
                          Early




                                                                                                                                                             Ch
                                          Frmation
                                     Siiya椎谷層
                                                                            Ch
                                                                                                                                            7000                                                                         7000
                                                                                                                                            6500                                                                         6500
                                                                                                   KKNPP                                    6000
                                                                                                                                                                                  KKNPP                                  6000
         新
        Neo-                後期
                           Late Upper Teradomari Fo
                                   上部寺泊層
                                                                    37.4                                                                    5500   37.4                                                                  5500
         第
        Gene
                                                                                                                                            5000
                                                                                                                                            4500
                                                                                                                                                                                                                         5000
                                                                                                                                                                                                                         4500
         三                          Lower Teradomari                                                                                        4000
                                      下部寺泊層                                                                                                                                                                              4000
         紀       Mio-                   Formation
                                                                    37.3                                                                    3500
                                                                                                                                            3000
                                                                                                                                                   37.3                                                                  3500

                 中新世 Middle
                      中期                                                                                                                                                                                                 3000
                 Cene                Hitiya七谷層
                                           Formation
                                                                                                                                            2500
                                                                                                                                            2000
                                                                                                                                                                                                                         2500
                                                                                                                                                                                                                         2000
                                                                    37.2                                                                    1500   37.2                                                                  1500
                                                                                                                                            1000                                                                         1000
                                        Green tuff
                                        グリーンタフ                                                                                              500                                                                          500
                          Early
                           前期                                       37.1
                                                                                                                                            400
                                                                                                                                            300
                                                                                                                                                                                                                         400
                                                                                                                                                                                                                         300
                                                                                                                                                   37.1
                                                                                                                                            200                                                                          200
                                                                                                                                            100                                                                          100
                                                                                                                                            50
                                                                                                                                            0
                                                                                                                                                                                                  Lower                  50
                                                                     37
                                                                                                                     Siiya                          37
                                                                                                                                                                                                  Teradomari
                                                                                                                                                                                                                         0


                                                                                                                     Formation                                                                    Formation
                                                                    36.9                                                                           36.9
                                                                       138.4     138.5     138.6    138.7   138.8    138.9   139   139.1              138.4     138.5    138.6    138.7   138.8    138.9   139   139.1


                                                                                               Contours of surface depth of each Formation(for example)                                                                   9
Ⅴ.Published information related with this researching project (3/6)
③ Estimated source fault plane
 of Chuetu-Oki earthquake                                                               Fault plane with weak

 The Headquarters for Earthquake Research Promotion:
                                                                                         NW dip (high angle)
                                                                                                                                ■In a large sense, source fault of Niigata-ken
 The 175th Earthquake Research Committee Report
  (January 11 2008)
                                                                                                                                 Chuetu-Oki Earthquake is reverse fault
                                                                                                      NE                         with SE dip (inclination from sea to land).
                                                    Fault plane with SE dip
                                                     (low angle)                                                                 At northeast part of source area,source
                                                                                                                                 fault with NW dip (inclination from land to
                                                                                     Segment boundary
     Main                                                                                                                         sea) also ruptured .
     rupture
      area
                                           (ERI of University of Tokyo)                       Key map of estimated main rupture surface
                                                                                      Main rupture surface is approximated the area with slip displacement of
                                                                                                         more than about 1m by rectangle

                                                                                                                                            Niigata

                                                                                           Island of Sado



                                                                                                                                                        Kashiwazaki




                                                                                                                                                Latitude : 37.495°
                                                                                 Topend depth :                                                 Longitude : 138.653°
                                                                                    2.0km                                                       Strike : 220°
                                                                                                        Wi
                                   Topend depth                                                              dt




                                                                                                                               km
                                                                                                                  h1
                                      2.0km                                                                         4k



                                                                                                                               12
                                                                              Latitude : 37.409°                      m                         Topend depth :


                                                                                                                           h
                                                                                                                          dt
                                                                              Longitude : 138.460°                                                4.0km
                                                                              Strike : 40°                                Wi                            Topend depth :    Wi
                                                                                                                                                           2.0km               dt                       Topend depth :
                                                                                                                                                                                 h




                                                                                                                                                                                                   km
                                                                                                                                                                                     14
                                                                                                           Le n




                                                                                                                                                                                                          4.0km




                                                                                                                                                                                                  12
                                                                                                                                    Len                                                 km




                                                                                                                                                                                              h
                                                                                                             gth




                                                                                                                                                                                             dt
                                                                                                                                        g




                                                                                                                                                                                             Wi
                                                                                                                                      th
                                                                                                                  10k




                                                                                                                                        27 k

                                                                                                                                                         Bottomend
                                                                                                                   m




                                                                                                                                                                                     Dip
                                                                                                                                            m

 Distribution focal depth of aftershocks                                                                                                                 depth : 11.0km
     Blue line indicates source fault plane with NW dip and                     (Geographical Survey Institute)                                                                              Dip        Bottomend
     gray line indicates source fault plane with SE dip.                                                                                                                                                depth : 13.2km   10
Ⅴ. Published information related with this researching project(4/6)
  ④ Relation between source of Chuetu-Oki earthquake                                                                                      Sado marine
                                                                                                                                             basin

                                          and active fault                                                                                  Research

   The Headquarters for Earthquake Research Promotion
                                                                                      Geological                     Sado bank                area
                                                                                                                                                            Moving zone to continental
              : The 175th Earthquake Research Committee Report (January 11 2008)
                                                                                     structure in                                                              area of inclined axis
                                                                                      exploration                                                                    Continental shelf
                                                                                     marine area
■ Based on the structural exploration in marine area, it appears active             (Report Figure 2)
                                                                                                            Jyoetu
                                                                                                            marine
  fault and active folding structure which lengthen in almost the same                                       basin
                                                                                                                                                                              Izumozaki

  direction as source fault in the northwestern area from the source.
  It is estimated that these active structures were mainly formed by
  reverse fault activity with SE dip.
■ Submarine deformation caused by this earthquake was not confirmed.
  However, there is a possibility that the extension of source fault with                                     Deformation
                                                                                                                  zone
  SE dip estimated from focus distribution of aftershocks connects to                                         of erosional                             Kashiwazaki
                                                                                                                surface
  submarine active fault.
                                                                                                                                              Active fault
                                                                                                                                                                               Afte shock

     Research results by organizations
                                                                                                                                              (dot-line is Estimation)
                                                                                                                                                                               area
                                                                                                                                              Anticline
                                                                                                                                                                               Active
                                                                                                                                                 Syncline                      anticline


                     Sado
                                                                Watanabe et.al.
                                                                                           Typical figure of fault estimated from folding
                                                                                       structure of Line7 (Report Figure 9, indicated below)

                                                                                      Typical fault that can expound reflecting section and geological structure along Line7

                                                                                            Sado bank                        Sado marine basin                           Continental shelf




                                                                TEPCO              Aspect ratio = about 3:1
                                                                                                                                                                 Pattern diagram of
                                              KKNPP                                                                                                                     fault




                                                                                   Data from Advanced Industrial Science and Technology 11
                                                                                                                                       Focus
Ⅴ. Published information related with this researching project (5/6)                                                                   distribution of
                                                                                                                                       aftershocks
                                                                                                                                       near Asperity1
⑤ Information related with source model and strong motion prediction (1/2)                           Setting of source fault surface
■ Source fault model
   Kojiro Irikura Earthquake motion research institute (http://www.kojiro-irikura.jp) Dec. 28 2007
                                                                                                                                       Focus
                                                                                                                       Main
                                                                                                                      shock            distribution of
   Source model proposed by Irikura et.al. (SE dip model)                                                                              aftershocks
                                                                                                                                       near Asperity2
Set a source model focusing on Asperity3 which causes the strongest motion
to the site of KKNPP.
■ There is a possibility that this earthquake has three Asperities, because of
  three distinct pulses in waveforms observed in coastal area near source.                                                             Focus
                                                                                                                                       distribution of
   ・Asperity1 --- The northern part of source fault near the hypocenter                                                                after shocks
   ・Asperity2 --- The mid-part between Asperity1 and Asperity3                                                                         near Asperity3    Slope angle

   ・Asperity3 --- The southern part of source fault,near the place of end                                                                                        : 30°



                   of rupture
■ This model is consisted of one fault plane which has N37°E of strike and
  30°of dip estimated from focus distribution of aftershocks.
                                                                               Basing point
                                                                               (37.391, 138.341)
                                                                               Depth 5.5km




                                                                                                      Source model parameters




                         Mechanism of source model


                                                                                                                                                                12
                                                                                                                 ⑤ Information related with
Ⅴ. Published information related with this researching project (6/6)                                               source model and strong
                         〔Summary of analysis by Irikura et. al.〕                                                  motion prediction (2/2)
                                                                                                                 ■ Example of simulation and
■The vibration amplification from seismic bedrock to the site is large at area of near KKNPP.                      analysis of observed records
■More study is needed for radiation characteristics of seismic wave , directivity effect and                       using source model with SE dip
 focusing effect from the source.                                                                                Irikura research institute
 ・ The position of Asperity3 corresponds to the direction which make radiation characteristics for the           (http://www.kojiro-irikura.jp)
                                                                                                                                      December 28 2007
   KKNPP largest.
 ・ There is a possibility that the strong pulse which was observed on surface and basement of UNIT
   K1 was formed by focusing from compositive effect of rupture process of Asperity3 and influence
   of wave propagation.                                                                                                                                              Magnetic north
                                                                                                                                                                        True north
                                                                                                                                                                         North-south axis
 ⇒ In order to study the strong pulse in detail, the investigation of three-dimensional structure of                                                                     of the plant


    underground from the source to the site is necessary.
                                                                                                               KKZ1                                           KKZ5
  〔Comparison between synthesized and observed motions (velocity waveform) 〕                                                                                 Under ground station
                                                                                     obs                                                                     near UNIT K6

                                                                                     anl
                                                                                                                                                            Under ground station
                                                                                                   Surface station near UNIT K1                             near UNIT K5
                                                                                                                                          Surface station
                                                                                                    Under ground station                  near UNIT K5
                                                                                                    near UNIT K1                     Service hole                      Existing
                                                                                                                                                                       seismometer
                                                                                                                                  KSH                                  New seismometer
                                                                                                                                                                       Existing and New
                                                                                                                                                                       seismometer




                                                                                                                                   Main
                                                                                                                                  本震
                                                                                                                                  shock




                                                                                                     Positional relation with radiation
                                                                                                    characteristics of Asperity 1 and 3
                                                                                                         and the site of KKNPP                                                            13
14
Published information for analyses of source                                                                               ERI Tokyo Univ. (Koketsu et al.)
                                                                                                                                 〔NW dip / SE dip〕
                                      and ground motions                                                         ■Character of Ground Motions : Three pulses
 Data on relation between source fault and surrounding active faults                                                  1st pulse     3rd pulse
                                                                                                                            2nd pulse(?)
   ■ Evaluation of Source model and ground motion
                         NIDE 〔NW dip / SE dip〕




                                               )
                                           di p
                                       E
                                     (S            )
                                lB             dip
                              de           W
                         mo           (N                                                                            Observed accle. at KKNPP (from TEPCO)
                                 lA
                               de
                          mo

                                                                            F-net
                                                                            Mw
                                                                            depth
                                                                            strike
                                                                            dip angle
                                                                            rake angle

                                                                                                                    SE dip                       NW dip


                                                                                               Source fault assumed by inversion using teleseismic body waves and strong
                                                                                               motion records (internal tone indicates slip distribution)
                                                                                               Asperity assumed by empirical Green’s function method
                                                                                               Hypocenter : depth 9km             Aftershock distribution

                                                                                           In case of focus depth of about 9-10km, Result of waveform inversion
                                                                                           analyses using teleseismic body waves and strong motions of near source
                                                                                           agree well.
       model A : NW dip                                model B : SE dip                    In case of fault with east dip, Results of waveform inversion analyses using
       strike : 215 / dip angle : 49                   strike : 49 / dip angle : 42        teleseismic body waves agrees well. However, it is hard at this moment to
                                                                                           conclude fault plane due to analyses using strong motion inversion and
                                                              (refer to NIED HP)           empirical Green’s function method.
                                                                                         (Seismic design subcommittee 24th.Aug.2007 document 13-3-6) support documentation
                                                                                                                                                                        15
Method for studying earthquake motions
 Study for the influence of 3-D structure in underground affecting ground motions
  In order to evaluate the influence of 3-D structure affecting observed ground motions (pulse generation, ground motion
  characteristic, etc ) in the site of KKNPP, Analysis using the simplified source model (point source) is carried out. Point
  sources is sat at asperity positions of north and south sides in source area , bedrock motions under the three evaluating
  points (UNIT K1, service hole and UNIT K5) by using discrete wave-number method and 3-D finite-difference method
  (FDM) is calculated, and the following terms are studied for evaluating the influence of 3-D structure.
  ・Difference of ground motions at each estimating point                                 Checking the influence of 3-D structure at each
    obtained by using 1-D and 3-D analytical model                                       estimating point
  ・Difference of ground motions cased by positional relation                             Checking the relation between the influence of 3-D
    of source and evaluating points                                                      structure and location of source and evaluating points
  ・Characteristics of wave propagation from each source to
   the target site and surrounding region (Checking wave                                 Checking local vibrational amplification caused by the
   concentration at target site caused by wave propagation)                              inflence of 3-D structure
                                                                                               ■ 3-D structure model                          ■ 1-D layer model
  KK7                                KK1                                                  K7                           K1
                    KSH                                                                                                                K7              SH               K1
                                                                                                         SH
                                                      Estimation of exposed bedrock
                                                       敷地内地盤・建屋地震動観測
                                                      motion by observed motion at
                                                       記録による解放基盤波の推定
                                                      the site and building
                                 Esitimation of
                                  解放基盤波
                                 bedrock
               site effect
             サイト増幅特性                  推定
                                 motion


                               Estimation of
                                   地震基盤波              Estimation of characteristics
                                                         3次元地下構造モデルによる
          Characteristics of           bedrock
                               seismic推定              of propagation path and site
                                                       (震源~地震基盤~解放基盤)
          propagation path
             伝播経路特性            motion                 effects by 3-D structure model
                                                       伝播経路・サイト増幅特性の推定




                                                                                                                 point source
                                                                                                                (Asperity position)
                                                       Forward
                                                       フォワード
                                       source          modeling
                                                       モデリング
                                        震源特性
                                    Characteristics
        asperity position
         (アスペリティ位置)
                                                                                             Analysis using 3-D FDM                 Analysis using discrete wave number
                                                                                                                                                  method



                                                                                       Study on the difference of wave               Comparison of waveforms and
                                                                                       propagation caused by different positional    response spectra obtained from
                                                                                       relation of source and evaluating points      different positional relation of sources
                                                                                                                                     and evaluating points
                                                                                                                                                  support documentation 16
Ⅴ.Published information related with this researching project (appendix)
              East                                       Underground structure of source area and circumference of the KKNPP
           longitude                                                                                              (Estimation)
 North                                              Uo        Sy         Na           Uo        Sy         Na           Uo        Sy         Na           Uo        Sy         Na
lstitude                                                                                                                                                       Ny        LTd        BS
                                本震
                                 Main
                                shock
                                                         Ny        LTd        BS           Ny        LTd        BS           Ny        LTd        BS




                                 Strongest after
                               最大余震
                                 shock




                             Kashiwasaki-Kariwa
                             柏崎刈羽サイト
                               site




                  Uo
                       Ny
                  Sy
                       LTd
                  Na                                               Viewing point                     Uo : Uonuma Group
                       BS
                                                                                                     Ny : Nishiyama Formation                                  JNES :Study of probabilistic method
                                                                                   North
                                                                                                     Sy : Shiiya Formation                                     concerning earthquake
                                                                                                     LTd: Lower Teradomari Formation                            = Evaluation of ground motion
                                                                                                                                                               characteristics based on identification
                  Uo                                                                                 Na : Nanatani Formation
                       Ny                                                                                                                                      of underground deeper structure =
                  Sy                                                                                 Bs :Basement rocks                                        JNES/SAE05-48, 2005.12)
                       LTd
                  Na
                        BS


                                                                                                                                                        魚沼層群1 : Vs = 0.6 km/s
                                                                                                                                                       Uonuma Group 1Vs0.6km/s
                                                                                                                                                        魚沼層群2 : Vs = 0.8 km/s
                                                                                                                                                       Uonuma Group 2Vs0.8km/s
                                                                                                                                  KKNP                 魚沼層群3 Vs1.3km/s
                                                                                                                                                       Uonuma Group 3 : Vs = 1.3 km/s
                  Uo
                       Ny
                  Sy
                       LTd
                                                                                                                                                                                     西山層(Vs1.4km/s)
                                                                                                                                                                                     Nishiyama Formation (Vs = 1.4 km/s)
                  Na
                       BS                                                                                                                                                            Shiiya and Upper Teradomari Formation
                                                                                                                                                                                     椎谷層+上部寺泊層(Vs1.7km/s)
                                                                                                                                                                                                            (Vs = 1.7 km/s)
                                                                                                                                                                                     Lower Teradomari Formation
                                                                                                                                                                                     下部寺泊層(Vs2.0km/s)
                                                                                                                                                                                                            (Vs = 2.0 km/s)
                                                                                                                                                                                     七谷層+グリーンタフ(Vs2.4km/s)
                                                                                                                                                                                     Nanatani Formation and Green tuff
                                                                                                                                                                                                            (Vs = 2.4 km/s)
                  Uo
                       Ny
                                                                                                                                                                                     基盤岩類(Vs3.0km/s)
                                                                                                                                                                                     Basement rocks (Vs = 3.0 km/s)
                  Sy
                       LTd
                  Na

                                                   (depth scale = horizontal×1.5)                                        about 8.2km
                                                                                                                         約8.2km
                       BS                          (縦横縮尺比1.5倍)
                                                                                                             約44km
                                                                                                           about 44km                                                                                              17
                                                                                                                                                                                                             Appendix

				
DOCUMENT INFO