EXPERIMENTAL RESEARCH ON SOIL-WATER CHARACTERISTICS CURVES OF UNSATURATED LATERITE IN NORTHERN SHAANXI PROVINCE

This paper studies the relationship among the matric suction, dry density, water content, saturation and volumetric water content of Baode laterite. The water content of 36groups of experimental specimens under different water contents and dry densities are measured with filter paper method in laboratory. The associated matric suctions are computed. The soil-water characteristics curves(SWCC)for unsaturated Baode laterite under different dry densities are obtained. The results show that the relationships among the matric suction, dry density, saturation and volumetric water content are of different characteristics at different water contents. The matric suction is not sensitive to changes of dry density, saturation and volumetric water content for low water content laterite. But it is contrary for high water content laterite. Relationships among matric suction, water content, saturation and volumetric water content are nonlinear. Matrix suction decreases sharply with the increase of water content, saturation and volumetric water content with the same dry density.