Evaluation of Compressibility for Normally Consolidated South-east Coast Clay Using CPT and DMT

Abstract A series of in-situ and laboratory tests were performed for the clayey soils of Busan area in order to develop the methods to evaluate the compressibility using CPT and DMT results. The laboratory tests show that the clayey layers of Busan areas are normally consolidated, and their compression indices are turned out to be 0.5～1.3. From the analysis of test results, correlation factors between the cone resistance and constrained modulus (  m and  n ) are observed to decrease with increasing plasticity index, and the correlation factor between the dilatometer modulus and constrained modulus (R M ) increases with 1/I D . Based on these relationships, the methods evaluating the constrained modulus from CPT and DMT results are suggested. It is shown that the prediction method by CPT underestimates the constrained modulus of improved ground, whereas the prediction method by DMT is suitable for evaluating the constrained modulus of improved and unimproved ground. 요 지 본 연구는 CPT와 DMT를 이용한 부산지역 점토 압축성 추정에 관한 것으로 , 이를 위해 부산신항과 녹산점토에 대해 현장시험 및 실내시험을 수행하였다 . 압밀시험 결과 부산신항 및 녹산 점토는 정규압밀점토이며 , 압축지수는 0.5～1.3로 나타났다. 분석결과에 의하면 콘저항치와 횡방향구속 변형계수의 상관계수인