Experimental Study on Stress-Dependent Soil Water Characteristic Curve of a Recompacted Expansive Soil

In order to investigate stress-dependent soil water characteristic curve of recompacted expansive soil and the changes of soil-water characteristic under vertical stress in terms of soil fabric and pore size distribution, pressure plate tests scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP) tests were conducted on a recompacted medium-expansive clay. The test results show that under an applied vertical stress, the air-entry value of a SDSWCC was greater than that of SWCC obtained under zero stress. No distinct hysteresis within a dry-wet cycle of SDSWCC could be found. The change of SWCC of the expansive soil under the applied stress could be mainly attributed to the rearrangement of aggregate and the compression of pores in the soil.