Preliminary study on soil-water characteristics of two expansive soils

Some preliminary results of laboratory tests on soil-water characteristics for two expansive soils from mainland China are presented in this paper. The test equipment adopted include conventional pressure plate extractors, newly developed 1D and isotropic stress control apparatuses. Effects of initial water content, soil structure, drying and wetting cycles and stress state on the soil-water characteristic curves of the expansive soils are addressed and compared with results from a weathered volcanic soil. Stress effects are more significant on SWCCs of the expansive soils than the weathered soil. Due to the distinct swelling characteristics, the volumetric water contents along the wetting path of the second are substantially higher than those of the first wetting cycle