Effect of Density on the Soil-Water-Retention Behaviour of Compacted Soil

This paper presents a series of experimental results obtained from wetting and/or drying cyclic tests and constant suction triaxial tests on unsaturated compacted clay with different initial densities using two suction-controllable triaxial apparatus. The primary objective of this research is to investigate the influence of the soil density on the soil-water-retention behaviour. The initial density and initial degree of saturation were controlled by changing the compaction energy using clay powders with almost the same water content. The test results contain the water-retention curves and deformation behavior at different initial densities using different specimens and one specimen before and after collapse. The test data indicate that the measured water-retention curves vary with the current specimen density. A denser specimen results in a higher degree of saturation at the same imposed suction, which implies that the water-retention curve shifts to the right in the ln s-S_r plane.