Evolution of slope seepage field and stability assessment under rainfall conditions

To reveal the mechanism of the sliding instability in slopes under the coupling effect of rainfall intensity, duration, groundwater level, and geological structure, a bedding cutting slope of strongly weathered soil-rock mixture in southern China was tanken as the research object. Engineering geological survey was conducted to analyze the landslide. Based on saturated-unsaturated seepage theory, a finite element model under infiltration conditions was established to simulate the spatiotemporal evolution of pore water pressure, volumetric water content, and stability under the influences of various factors. The results show that heavy rainfall rapidly weakens shallow matric suction and raises pore water pressure and water content, resulting in a significant decrease in stability within a short time. Extension of duration leads to the advance of wetting front and the decrease of stability. High groundwater level superimposed heavy rainfall or long duration presents the most unfavorable stability.