taiwan/us/japan ws recent development of ps logging in japan yoshi iwasaki geo-research inst., osaka...

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Taiwan/US/Japan WS Recent Development of PS Logging in Japan Yoshi Iwasaki Geo-Research Inst., Osaka 台台 台台台 台台 ・・ /Taiwan US Japan Workshop on Liquefac tion November 3-4, 2003, Hsinchu, Taiwan

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  • Slide 1
  • Taiwan/US/Japan WS Recent Development of PS Logging in Japan Yoshi Iwasaki Geo-Research Inst., Osaka /Taiwan US Japan Workshop on Liquefaction November 3-4, 2003, Hsinchu, Taiwan
  • Slide 2
  • Kitsunezaki invented suspension PS-logging system Vs, Vp(km/sec) Poisson's Ratio Vs, Vp(km/sec) Poisson's Ratio Vs, Vp(km/sec) Poisson's Ratio Borehole pick In loose and soft ground, it is difficult to perform logging by borehole pick.
  • Slide 3
  • Development of Suspension System Liquid moves with surrounding ground. If the pick up is the same density as the liquid Suspension sensor detects shear wave in liquid.
  • Slide 4
  • Shear Wave Source S-wave Pressure increase decrease Electromagnetic hammer
  • Slide 5
  • Tube waves Source does not always work as designed. Hammer action may induce some volume change. Compression/Expansion in all direction induces tube waves. To cut tube wave, balloon was inserted between source and sensor. Sensor Balloon filter Source
  • Slide 6
  • Patent Kitsunezaki obtained Japanese Patent on Suspension PS-logging. He does not ask to pay royalty but to open the PS-velocity data to be disclosed insisting the geological data should be open to everybody. OYO insisted the patent is invalid.
  • Slide 7
  • Under sea logging for Kansai airport Diver was sent down to the bottom of the sea to strike wooden plate by sledge hammer. Experimental Study by Port and Harbor Research Institute
  • Slide 8
  • Kansai Air port
  • Slide 9
  • Cross Correlation Cross Correlation between 6m(N) and 7m(N)
  • Slide 10
  • Schlumberger
  • Slide 11
  • Automatic Velocity Determination
  • Slide 12
  • Waves from Monopole source Shear wave velocity is smaller than Fluid wave
  • Slide 13
  • Waves from monopole source Shear wave velocity is larger than fluid wave.
  • Slide 14
  • Waves from dipole source
  • Slide 15
  • PS-logging at Kobe 1700m in depth Granite Pleistocene Holocene (Quaternary)
  • Slide 16
  • PS-logging at Kobe
  • Slide 17
  • Conclusion Suspension type PS-logging tool has been invented and used widely to measure PS- velocity in geotechnical engineering for shallow depth. Schlumberger has further developed the system to process automatic velocity determination and for deeper application. The same system as Schlumberger may be developed for shallow and smaller diameter in near future.