Effect of Drying and Wetting SWCCs on Unsaturated Soil Slopes

The soil water characteristic curve (SWCC) exhibits hysteresis. It is the relation between soil water and soil suction. Desorption (drying) and sorption (wetting) can be used to obtain SWCC. The suction is different in drying and wetting SWCC paths. The slope failures generally take place in wetting SWCC. Therefore, a few efforts have been made in this direction to investigate the effect of drying and wetting SWCCs on slope stability. In this study, the change in factor of safety (FoS) considering drying and wetting SWCCs of unsaturated infinite slope is presented. It is noted that there is a substantial change in the FoS during drying and wetting cycles. A significant difference in the fitting parameters of SWCC for drying and wetting cycles can be observed. In addition, a notable change can be observed in the suction stress of the unsaturated soil slope obtained using both drying and wetting SWCCs. Additionally, the FoS values obtained from experimental data are compared with the correlations available for wetting SWCC in the literature. The correlations available in the literature are in good agreement with the experimental data. The present study highlights the importance of wetting SWCC on the stability analysis of unsaturated soil slopes