Random Finite-Element Analysis of Slope Considering Strength Anisotropy and Spatial Variability of Soil

Soil is a complex material that exhibits both spatial variability and anisotropy. For simplicity, the traditional approach for analyzing slope stability often assumes that soil is homogeneous or isotropic, which can lead to an overestimation of slope stability and reliability. To address this issue, a novel approach is proposed in this study that uses an anisotropic yield criterion based on the random finite-element method to evaluate the influence of strength anisotropy on slope stability, while accounting for the influence of spatial variability on reliability. The proposed approach is applied to a typical case of slope reliability analysis. It is shown that the results of the proposed approach are consistent with those of previous studies and OPTUM G2 outcomes. The assessment involves determining the safety factors for both homogeneous and anisotropic conditions, while also taking into account the probability of failure in the presence of spatial variability. It is found that strength anisotropy significantly affects slope stability and reliability, as the factor of safety decreases from 1.255 to 1.037 and the probability of failure increases from 3.5% to 52.1% when considering strength anisotropy (n=0.707, xi=11.25 degrees). In addition, a sensitivity analysis is performed to investigate the influence of slope geometric parameters, strength anisotropic parameters, and spatial variability parameters on slope stability and reliability.