65 Behavior of Calcareous Sand under Triaxial Drained Shear Condition

Calcareous sediments generally consists of the remains of marine organism, which tends to crush relatively easily under load, compared to terrigenous materials. This paper presents shear laboratory tests carried out on calcareous sand taken from the South China Sea, and points out that the shear behavior of calcareous sand under medium confining pressures is just similar to that of terrigenous sand under high stress levels. The volumetric strain is larger than that of terrigenous sand when sheared because of particle breakage. The relation of the dilatancy, ratio of stress and confining pressures is also discussed in this paper. The results indicate that the dilatancy and ratio of stress are decreasing as the confining pressures increases.