Cyclic Threshold Shearing Strains of Sands Based on Pore Water Pressure Buildup and Variations of Deformation Characteristics

간극수압증가와 동적변형특성 변화에 근거한 사질토 지반의 반복한계전단변형률

In this paper, the existing Stokoe type torsional shear equipment is modified to saturate the specimen and measure excess pore water pressure during undrained testing. Two types of sands, Geumgang and Toyoura sands, were collected and TS tests were performed at various densities drainage conditions, and confining pressures. The cyclic threshold shearing strains were estimated based on the variations of shear modulus, material damping ratio and pore pressures with loading cycles. The effects of relative density, confining pressure, and drainage condition on the cyclic threshold shearing strains were investigated.