DOI: https://doi.org/10.21203/rs.3.rs-670897/v1
Based on the Darcy's law and water balanceprinciple,some infiltration models have been proposed,but most of these models are not suitable for simulating infiltration into layered soils during unsteady rainfall. In this paper, a simple modelfor simulating water infiltration into the two-layer soil slopesduring unsteadyrainfallwasproposed, combined with the limit equilibrium methodto analyze the stability of thetwo-layer soil slope.The water infiltration rate of slopes depends on rainfall intensity and the actual infiltration capacity of soils. The proposedmodelhas been successfully applied to three cases (steady rainfall and homogeneous slope, unsteady rainfall and homogeneous slope,unsteady rainfall and two-layer soil slope), and it can be also combined with probabilistic methods to calculate the failure probability of slopes.Compared with the Richards model, the combination of the proposed model and the random field method can quickly obtain the failure probability of the slope.