Stability evaluation of the high fill deposit slope subjected to rainfall considering water deterioration

In this study, three various types of rainfall with the measured rainfall events and data are used to analyze the stability of the high-fill deposit slope taking the influence of water deterioration into account. Under natural and saturated fully submerged conditions, the mechanical behaviors of the S-RM inside the slope are investigated, and the test results are taken into consideration in the numerical analyses as a reference to water deterioration. The test results show that the loss of the soil that filled in the spaces between the rock blocks due to the water migration has a clear negative impact on the shear strength and friction angle of S-RM. According to the simulation analyses, the negative pore water pressure (matric suction) exhibits a greater area of dissipation under the multi-peak type rainfall with the assistance of the antecedent rainfall, and the evident decrease in safety factor with the smallest value is also found with the upward movement of the potential sliding surface. When the water deterioration is taken into account, the deposit slope stability is more susceptible to rainwater infiltration, and the position of the potential sliding surface is more consistent with the matric suction dissipation. The results of this study support the notion that persistent antecedent rainfall and water deterioration are two key aspects in the stability of the high-fill deposit slope.