BASE GROUND DISASTERS DUE TO EARTHQUAKE

EXAMPLES ARE GIVEN OF DAMAGES CAUSED BY A BASE GROUND DISASTER DURING AN EARTHQUAKE TIME. SEVERE DAMAGES UPON STRUCTURES ARE CAUSED BY WEAKENING AND MOVEMENT OF A BASE GROUND DURING AN EARTHQUAKE TIME. IT SEEMS EVIDENT THAT SEISMIC DISASTER CONCENTRATES ON A LOOSE BASE GROUND AND THAT LOOSE SANDY GROUND IS VULNERABLE TO SEISMIC OSCILLATIONS. THE DEGREE OF LOOSENESS MAY BE DETERMINED BY MEANS OF PENETRATION TESTS. THE DEGREE OF SAFETY OF A STRUCTURE WITH A COMPARATIVELY SIMPLE CONSTRUCTION MAY BE CONFIRMED IN KINETICS CALCULATION. HOWEVER, THE PENETRATION TESTS SHOW THAT THE STATUS OF A BASE GROUND IS HIGHLY COMPOSITE. THE OSCILLATION OF A GROUND SURFACE IS VARIABLE BY THE STATUS OF THE BASE GROUND, THE CONFIGURATION OF THE GROUND SURFACE, ETC. A CRACK AND A SMALL FAULT MAY OCCUR ON LEVEL GROUND, BUT AN OBLIQUE SURFACE AND AN EMBANKMENT ARE STILL MORE PRONE TO THESE DAMAGES. THE LIQUEFACTION PHENOMENON OF SUBTERRANEAN SAND DOES NOT NECESSARILY OCCUR UNDER A UNIFORM CONDITION. A FLUID MIXTURE OF WATER AND LIQUEFIED SAND OCCURING UNDERGROUND WOULD BLOW OUT OF THE GROUND SURFACE, PENETRATING A VULNERABLE POINT OF A SURFACE LAYER. THIS BLOWING MAY BE SEVERAL MINUTES AFTER A SEISMIC VIBRATION, AND MAY GO AS HIGH AS SEVERAL METERS IN ACCORDANCE WITH THE PRESSURE. A LIQUEFACTION OF SAND DECREASES ITS BEARING FORCE AND LATERAL RESISTIVITY UPON THE BASE GROUND. INSTRUMENTS ARE DISCUSSED FOR MEASURING DIFFERENT EARTH CONSTANTS TO BE APPLIED TO A RESPONSE ANALYSIS OF A STRUCTURE.

  • Supplemental Notes:
    • Vol 11, pp 1-32, 21 FIG, 1 TAB
  • Corporate Authors:

    Public Works Res Inst, Cm /Japan

    /Journal of Research
    ,   United States 
  • Authors:
    • Fukuoka, M
  • Publication Date: 1966

Subject/Index Terms

Filing Info

  • Accession Number: 00234363
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jun 18 1994 12:00AM