ANALYSES OF EARTHQUAKE GROUND MOTIONS AT JAPANESE SITES

PROCEDURES DEVELOPED FOR ANALYZING AND PREDICTING THE GROUND SURFACE MOTION DEVELOPED BY EARTHQUAKES AT DIFFERENT SITES INVOLVE THE APPLICATION OF THE FOLLOWING STEPS: (1) AN ASSESSMENT OF THE CHARACTERISTICS OF THE MOTIONS INDUCED IN THE ROCK UNDERLYING THE SITE BY THE PARTICULAR EARTHQUAKE INVOLVED, (2) A DETERMINATION OF THE TYPE AND EXTENT OF THE VARIOUS SOIL LAYERS EXTENDING FROM THE GROUND SURFACE TO THE BASEMENT ROCK AT THE SITE, (3) AN ANALYSIS OF THE RESPONSE OF THE SOIL DEPOSIT TO THE BASE MOTIONS DEVELOPED IN THE UNDERLYING ROCK, AND (4) THE DEVELOPMENT OF SUITABLE ENGINEERING PROCEDURES FOR DETERMINING THE SOIL PROPERTIES TO BE INCORPORATED IN THE ANALYSES AND FOR APPLYING THE ANALYSES TO ACTUAL SITES. THE RESULTS OF ANALYSES OF GROUND RESPONSE FOR EIGHT SITES IN JAPAN WHERE GROUND MOTIONS WERE RECORDED IN RECENT EARTHQUAKES ARE PRESENTED. A COMPARISON OF THE COMPUTED AND RECORDED MOTIONS IS SUMMARIZED IN A TABLE. IN SPITE OF THE ASSUMPTIONS MADE IN THE ANALYSES DUE TO LACK OF KNOWLEDGE OF THE SOIL CONDITIONS BELOW ABOUT 150 FOOT DEPTH, THE OVERALL MAGNITUDES AND FREQUENCY CHARACTERISTICS OF THE COMPUTED MOTIONS ARE IN GOOD AGREEMENT WITH THOSE OF THE RECORDED MOTIONS. FOR FIVE OF THE EIGHT SITES, THE AVERAGE VALUE OF THE COMPUTED GROUND SURFACE ACCELERATION WAS WITHIN 14% OF THE RECORDED MAXIMUM ACCELERATION, THE DEVIATIONS FOR THE OTHER THREE CASES BEING 19, 36 AND 50%. A SOMEWHAT SIMILAR DEGREE OF SUCCESS WAS ACHIEVED IN THE COMPUTATION OF SPECTRAL FORMS WITH GOOD AGREEMENT BEING OBTAINED IN ABOUT SIX OF THE EIGHT CASES EXAMINED. THIS SUGGESTS THAT WHERE SOIL CONDITIONS CAN BE RELIABLY DETERMINED, THE ANALYTICAL PROCEDURES USED OFFER GOOD PROMISE AS A MEANS OF CONSIDERING THE EFFECTS OF LOCAL SOIL CONDITIONS IN THE PREDICTION OF GROUND RESPONSE DURING EARTHQUAKES.

  • Supplemental Notes:
    • 15 Pp, 9 FiG, 3 TAB, 13 REF
  • Corporate Authors:

    University of California, Berkeley

    Berkeley, CA  USA  94720
  • Authors:
    • Kiefer, F W
    • Seed, H B
    • Idriss, I M
  • Publication Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 00235732
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jul 21 1970 12:00AM