Probabilistic assessment of slope failure considering anisotropic spatial variability of soil properties

Anisotropic spatial variability of soil properties is frequently encountered in geotechnical engineering practice due to the complex depositional process. To quantitatively evaluate the response of slope failure related to anisotropic spatial variability of soil properties and reveal the underlying influence of anisotropic spatial variability of soil properties on the slope reliability, this study integrates the random finite difference method (RFDM) into a probabilistic assessment framework and adopts general spatial variability and a cohesive-frictional soil slope example for illustration. A parametric analysis is carried out to investigate the influence of general anisotropic spatial variability of soil properties on slope failure probability and failure characteristics. The results show that the directional angles of scales of fluctuation of general anisotropic spatial variability significantly affect the slope failure probability. The dominant failure mode is the intermediate type in most cases of general anisotropic spatial variability, which is distinguished from the shallow failure mode occurring in the homogenous state. Overestimation of cross-correlation between c and φ (), scales of fluctuation ( and ) in general anisotropic spatially variable soils significantly influences the average slip mass volumes of deep and multi-slip failure mode. Compared with transverse anisotropic spatial variability, general anisotropic spatial variability significantly amplifies the effects of , and on slope reliability.