Response of Open-ended Pipe Pile Foundation at Offshore Sites to Seaquake Induced by the Vertical Seismic Excitation of the Seafloor

해저면의 수직 지진 진동에 의해 유발된 해진에 대한 해상 개단 강관 말뚝 기초의 거동

  • 최용규 (경성대학교 건설·환경공학부) ;
  • 남문석 (경성대학교 건설·환경공학부)
  • Published : 1998.03.01

Abstract

During an earthquake, there are three main components of excitation : horizontal excitation of the ground, vertical excitation of the pile due to superstructure feedback produced by vertical excitation of the ground, and the seawater excitation induced by the vertical ground shaking, that is, "the seaquake." These excitations could have effects on the soil plugs in open-ended pie piles installed at offshore sites. In this study, seaquake excitation induced by the vertical ground shaking was simulated by pulsing the water pressure at the seabed. During a seaquake, due to the induced excess porewater pressure and pressure gradients in the soil, the capacity of open-ended pipe piles installed in a simulated sea depth of greate than 220 m was reduced serevely and the soil plugging resistance was degraded by more than 80% The soil plug was failed because of eh upward seepage forces that developed in the soil plug due to excess pore water pressure produced in the bottom of the soil plug during the seaquake, The compressive capacity of ar open-ended pile in a simulated sea depth of less than 220 m was reduced only by about 10% and the soil plug resistance was degraded by less than 5%.s than 5%.

Keywords

induced seaquake;open-ended pile foundation;ultimate compressive pile capacity;soli plugging resistance;deep sea;excess pare water pressure;seepage forces

References

  1. Ph. D. Thesis, Department of Civil and Environmental Engineering Response of Tension Piles to Simulated Seismic Motion in Saturated Fine Sand Ochoa, M.
  2. Journal of Waterways, Ports, Coastal, and Ocean Engineering v.114 no.4 Earthquake response of submerged circular arch Williams, A. N.;Mau, S. T.
  3. Porceedings of the 8th (1998) International Offshore and Polar Engineering Conference Response of soil plug to seaquake induced by vertical seismic excitation Choi, Y.-K.;O'Neill, M. W.
  4. Journal of Engineering Meahcnics v.109 no.1 Physical modeling of sea-seabed interactions Yamamoto, T.;Takahashi, S.;Schuckman, B.
  5. Journal of Geotechnical and Geoenvironmental Engineering v.123 no.10 Soil Plugging and relaxation in pipe pile during earthquake motion Choi, Y.-K.;O'Neill, M. W.
  6. Proceedings of the 20th Annual OTC v.2 Safety consideration of the TLP on earthquake wave propagated through seawater Kobayashi, H.;Sakuta, M.;Okamoto, O.;Hirakawa, S.
  7. Ph.D. Thesis, Dept. of Civil and Environmental Engineering Performance of Tension Piles during Simulated Ground Shaking and Seaquakes Rao, P. M.
  8. Proceedings of the 7th(1997) International Offshore and Polar Engineering Conference Response of soil plug to horizontal and vertical excitation Choi, Y.-K;O'Neill, M. W.
  9. Report No. UHCEE 90-09, Dept. of Civil and Environmental Enineering Response of tension piles to simulated seismic motion in saturated fine sand O'Neill, M. W.;Vipulanandan, C.;Ochoa, M.
  10. 한국지반공학회지 v.11 no.2 소형 압력토조내에 타입된 말뚝의 인발 거동과 극한 지지력 결정에 관한 연구 최용규