Wedge Failure Analyses of the Jointed Rock Slope Influenced by Foliations

Abstract

The stability of the slope is essentially controlled by the ratio between available shear strength and acting shear stress, expressed as the factor of safety, along the sliding surface. The slope is deemed stable if the computed factor of safety is larger than unitary and unstable if the computed factor of safety is less than unitary. Although the current analytical method for computing the factor of safety of the jointed rock slope subjected to wedge failure mechanisms allows predictions of the stability of the slope, it tends to oversimplify the key geological features that may influence the resulting factor of safety of the slope. The simplified analytical model was applied to determine the factor of safety of the physical jointed rock slope subjected to the wedge failure mechanisms. Furthermore, numerical model that incorporates key geological feature such as joints and foliations on the same physical case was built to simulate the stability of the jointed rock slope subjected to wedge failure mechanisms. The analytical model results indicate that the computed safety factor is above unitary, suggesting a stable slope while the numerical simulations result of the same physical slope predicted unstable slope. The obtained conservative factor of safety entails unrealistic predictions of the stability of the jointed rock slope subjected to wedge failure mechanisms. A numerical simulation model that incorporates key geological features could provide realistic predictions of the stability of the jointed rock slope subjected to wedge failure mechanisms.