Shear Strength and Volume Change of Unsaturated Collapsible Soil by CW Test

Abstract

Collapsible soil exhibited significant changes in volume upon addition of water content. This process causes serious damage to foundations built on such soil. Critical state theory has been extensively used to establish models for simulating elastic-plastic behavior of unsaturated soils. But, experimental works is relatively limited especially for collapsible clays. Based on this background, it is of extremely importance to experimentally investigate the shear strength characteristics and shearing induced volume change of these materials in unsaturated conditions. In this paper the shear strength and volume change behavior of a collapsible soil is studied using a series of Constant Water (CW) triaxial test at different matric suctions and net confining stress. The results indicate that the initial suction value and net confining stress have a great influence on the shear strength, pore-water pressure, and volume change behavior of the soil during shearing under the constant water content condition.