Study on the stability and disaster mechanism of layered soil slopes under heavy rain

Under the influence of rainfall, the failure mechanism and stability of layered slopes is one of the current hot topics. This paper aims to examine the influence of rainstorm conditions on the stability of layered soil slopes and analyze the inter infiltration rule and water-holding response characteristics through physical model tests and numerical simulation. The results demonstrate that the layered structure and inclination can affect the rainwater infiltration and stability of layered soil slopes under rainstorm conditions. Different inclinations greatly influence the safety factors of the layered soil slopes and the downdip slopes are more susceptible to landslides due to heavy rainfall. Meanwhile, the pore water pressure of the sand layer dissipates 90.95% and 70.45% under the horizontal layer and downdip layer, respectively. In addition, settlement occurs on the surface of the slope at the initial stage of rainfall. As rainwater continuously infiltrates, the slope’s surface expands unevenly. The expansion amplitudes of the shoulder and toe of the slope have a more extensive expansion range, which is crucial in landslide prevention and control. The results of the model test are consistent with the numerical simulation analysis. The results provide a theoretical basis for designing a stratified soil slope management plan.