A New Method of Liquefaction Evaluation Based on Disturbed State Concept

교란상태개념에 기초한 새로운 액상화 평가 방법

  • 박인준 (연세대학교 산업기술연구소 전문연구원) ;
  • 김수일 (연세대학교 토목공학과)
  • Published : 1998.06.01

Abstract

Although a number of methods have been proposed to predict the liquefaction potential, few methods have been developed by using the characteristic of material's microstructure. In this research, fundamental procedure is proposed for the assessment of liquefaction potential in saturated soils based on the Disturbed Sate Concept(DSC) model which can provide a unified constitutive model for the characterization of entire stress-strain behavior under cyclic loading. From this concept, the value of disturbance at threshold state (Critical Disturbance, $D_C$) in the deforming microstructure provides the basis for initial liquefaction. This method is verified with respect to data from Cyclic Truly Triaxial test for saturated Ottawa sand. Also, the relationship between liquefaction and initial confinig stress is defined using definition of $D_C$. It is believed that the new procedure for identifying liquefaction based on the DSC model can capture the behavior of liquefation, and as a result, it is shown to be on improvement over the available empirical procedures.

액상화 가능성을 예측하기위해 많은 방법들이 제안되어왔지만, 재료의 미세구조의 특성을 이용한 방법은 거의 없다. 본 연구에서는, 동하중을 받는 재료의 전체 응력-변형률의 특징에 대해 통합적 구성방식을 제공하는 교량상태개념(DSC)모델에 이론적 기초를 두며, 포화 사질토의 액상와 가능성을 평가하기 위한 새로운 방법을 제안한다. DSC이론으로부터, 미세구조의 변형시 재료내부 상태의 급격한 변화가 일어나는 시점의 교란도(한계교란도: Dc)를 초기 액상화 시기로 정의한다. 본 방법은 포화 Ottawa 모래를 이용한 진동 실삼축시험 결과로부토 얻은 자료를 이용하여 적합성이 검토되었다. 또한 본 연구로부터, 액상화와 초기 구속압사이의 관계가 Dc의 개념으로부터 밝혀졌다. 본 연구에서 제안한 새로운 액상화 평가방법은 액상화 거동을 예측할 수 있으며, 결론적으로 기존의 경험적 방법보다 향상된 방법이라고 사료된다.

Keywords

References

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