Behavior of unsaturated soil in triaxial test under undrained condition

摘要

In this study, the specimens desaturated from saturated state using the pressure plate method were applied to triaxial compression test under undarined condition, and the suction change and the deformation characteristics were investigated. When the degree of saturation in the specimen was relatively high, the pore water pressure in the specimen increased with compression and decreased with expansion in shear process. However, the pore water pressure in the specimen increased again regardless of the expansion when shear strain became larger. On the contrary, when the degree of saturation was low, the pore water pressure in the specimen increased with shear strain regardless of the volume change. On the failure criterion, it was found that the critical state line obtained from undrained compression test agreed with that obtained from drained compression test.