Cut soil slope stability analysis along National Highway at Wozeka–Gidole Road, Ethiopia

Abstract

The Wozeka–Gidole road in Ethiopia experiences frequent slope failure and triggered during road construction. This study identified the actually failed slope to verify numerical results of both limit equilibrium method (LEM) and finite element method (FEM) with the actually failed slope. Modeling of the actually failed slope with the FEM-based PLAXIS software and LEM-based SLOPE/W software had been used to calculate the factor of safety (FOS). The comparative study of the LE methods shows that The Bishop, Janbu, Morgenstern-Price, GLE and Spencer methods yield in most cases identical FOS for circular slip surface. However, the ordinary method may underestimate the FOS. All LE methods, except the Ordinary methods, estimate higher FOS than FE analysis in PLAXIS. Numerical results of both FEM and LEM verify instability of the slope. In general, the model provides the possible major causes of slope instability and their possible remedial measures in the study area.