EXPERIMENTAL STUDY OF SOIL-WATER CHARACTERISTICS CURVES OF EXPANSIVE SOIL UNDER WETTING CONDITION

The expansive soil in Hefei was studied． Osmotic method and filter paper method were used to measure the relationship between gravity water content and matrix suction in different initial dry densities． The relationship between void ratio and gravity water content of the soil was measured by wetting test． Then，according to the theoretical analysis，the soil-water characteristic curve (SWCC) considering the volume change of different initial dry densities was obtained． The results showed that the initial dry density had an influence on the SWCC merely to the water content of the soil samples near their saturation water content，and they were roughly coincident in middle matrix suction parts． Different initial dry densities had obvious influence on SWCC considering the volume change of wetting． When the soil moisture content closed to saturation，a cross in curves of volumetric water content and matrix suction in different initial dry densities appeared．