Stochastic Analysis of Rainfall-Induced Slope Instability and Steady-State Seepage Flow Using Random Finite-Element Method

Abstract

The stochastic analysis of unsaturated rainfall-induced slope instability has been studied by many researchers. However, the applicability of random FEM (RFEM) has not been used enough to assess the effect of the uncertainty of soil parameters and suction on these types of slope. In this study, considering the uncertainties of soil parameters leads to an uncertain wetting branch of the soil–water retention curve (SWRC); therefore, a stochastic permeability coefficient curve with respect to suction is obtained. For this purpose, a computer program has been coded to determine the reliability indices of unsaturated slopes under different rainfall intensities and seepage flow using RFEM. In a subsequent part of the paper, the functions of slip surface are obtained for different simulations and rainfall intensities by fitting the points with maximum shear strain. Finally, the uncertainties of slip surfaces are analyzed.