Probabilistic large deformation analysis of rainfall-induced slope failures considering spatial variability of saturated hydraulic conductivity
摘要
Determining post-failure characteristics of slopes under rainfall is an essential prerequisite for assessing and mitigating landslide risks. This study proposes a coupled hydro-mechanical framework that integrates the Random Limit Equilibrium and Material Point Methods (RLE-MPM). The post-failure characteristics, landslide types and probability of slope failure considering the spatial variability of saturated hydraulic conductivity (ks) are evaluated using this framework through probabilistic large deformation analyses. An infinite slope under rainfall and Tokai-Hokuriku expressway landslide in Japan are investigated, respectively, to illustrate the effectiveness of the proposed RLE-MPM framework. The influences of the rainfall duration as well as the coefficient of variation of mechanical parameters and ks on the slope post-failure characteristics are investigated. Results indicate that the proposed RLE-MPM framework is computationally more efficient in evaluating the slope post-failure characteristics and probability of slope failure than the Random Material Point Method (RMPM). Additionally, the spatial variability of ks significantly affects the means and coefficients of variation of slope post-failure characteristics. The failure characteristics of the Tokai-Hokuriku expressway landslide can be accurately predicted by using the proposed framework. This study highlights the necessity of considering the heterogeneity of soils in landslide movement prediction and risk assessment.