3D stability assessment of stepped slopes in inhomogeneous soils

Abstract

Stability assessment of slopes has historically been performed assuming soils to be homogeneous in two-dimensional (2D) cases. In real cases, soils are usually inhomogeneous, and each slope collapse indicates a three-dimensional (3D) nature. Based on a 3D rotational failure mechanism, this work develops an approach to account for the impact of the vertical strength inhomogeneity on the 3D stability of stepped slopes. Seismic actions are taken into account by introducing the concept of a horizontal seismic coefficient. An upper-bound expression for stability factors is derived in the light of the kinematic approach, and the most critical solution is obtained from an optimization programming. In comparison with the previously published solutions, the validity of the proposed method is shown. A sensitivity analysis is carried out to discuss parametric effects on the stability of 3D stepped inhomogeneous slopes.