Slope Crack Propagation Law and Numerical Simulation of Expansive Soil under Wetting-Drying Cycles

This study investigated the crack propagation law of expansive soil slopes under drying-wetting conditions and the influence of cracks on slopes by conducting a large-scale indoor slope test subjected to drying-wetting cycles. The change in soil moisture content at different depths during the drying-wetting cycles was monitored using a moisture content sensor, and the variation in crack depths in the expansive soil during the drying process was measured using a crack depth detector. The cracks on the slope's surface were processed using a self-made binarization program, and the crack evolution mechanism of the expansive soil during the drying process was analyzed. The rainfall-induced change in moisture content in the fractured soil was used to obtain the influence of moisture content change on expansive soils, and to analyze the dry-wet cycle failure mode of surface soil. The surface cracks of the soil were quantified by binary processing, and the area of the cracks and the area ratio of cracked soil to intact soil were calculated. Finally, by using PFC simulation software with the slope cracks and quantitative analysis results as parameters, it was confirmed that the greater the number of drying-wetting cycles, the greater the number of cracks, and the greater the damage to the slope.

Automated summary

This study investigated the crack propagation law and influence of cracks on expansive soil slopes under drying-wetting conditions through a large-scale indoor slope test. Soil moisture content change at different depths during drying-wetting cycles was monitored, and crack depths in the soil were measured. The cracks on the slope's surface were analyzed, and the influence of moisture content change on expansive soils and the failure mode of surface soil were determined. Quantification of surface cracks and simulation software confirmed the relationship between the number of drying-wetting cycles, the number of cracks, and the damage to the slope.