Excess Pore Water Pressure Response in Soft Clay under Embankment

성토하부 연약지반에서의 과잉간극수압 거동

  • Kim, Yun-Tae (Member, Senior Manager, LG Engrg. and Construction Corp.) ;
  • Kim, Nak-Kyung (Member, Assistant Professor, Dept. of Civil Engrg., Sungkyunkwan Univ.)
  • Published : 2002.06.01

Abstract

Increases in excess pore water pressure without change of surcharge load were reported in clay underneath embankment at Berthierville and Olga sites after the end of construction. These abnormal phenomena could not be explained by classical consolidation theory. This paper presents a nonlinear viscoplastic model to interpret an increase in pore water pressure on natural clay, The proposed model can consider the combined processes of pore water pressure dissipation according to Darcy's law and pore water pressure generation due to viscoplastic strain, as well as time-dependent viscoplastic behaviour and strain rate dependency of preconsolidation pressure. The calculated results using numerical analysis are compared with measured ones under embankments built on soft clay at Berthierville and Olga in Quebec, Canada. It may be possible to explain the phenomenon of excess pore water pressure increase after the end of construction using the proposed nonlinear viscoplastic model.

성토하부 연약지반에서 상재하중의 변화가 없는 상태에서 과잉간극수압의 증가가 Berthierville와 Olga 지역에서 보고되었다. 이와같은 비정상적인 현상들을 고전적인 압밀이론으로 설명하기는 어렵다. 본 논문은 비선형 점소성모델윽 사용하여 자연점토지반에서 유발되는 간극수압 증가를 설명하였다. 제안된 모델은 Darcy 법칙에 의한 간극수압 소산과 점소성 변형에 의한 간극수압 생성에 대한 복합적인 거동을 모사할 뿐만 아니라 시간 의존적인 점소성 거동과 변형을 속도 의존적인 선행압밀하중 특성을 표현할 수 있다. 수치해석기법을 적용하여 Berthierville각 Olga 지역의 성토과정을 해석하였으며, 수치해석 결과와 계측된 값을 비교한 결과 제안된 비선형 점소성모델볶 사용하여 성토가 끝난 직후 간극수압의 증가현상을 설명할 수 있다.

Keywords

References

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