Loss of stability in geosynthetic-reinforced slopes

Abstract

Geosynthetics are commonly considered to provide restoring forces against sliding during overall slope stability analyses. Where a slipping surface intersects a geosynthetic layer, the geosynthetic layer produces a reaction force either in the opposite direction of sliding, in the direction of the geosynthetic alignment, or in some intermediate direction. The provision of geosynthetic reinforcements typically increases the factor of safety in limit equilibrium against overall sliding in the design of a mechanically stabilized earth (MSE) wall, and for this reason has become popular among practitioners. However, geosynthetics are typically installed in contiguous layers. These layers are potential interfaces for sliding which need to be checked with respect to slope stability. In other words, it is possible for a slope to become unstable via partial sliding along the interface of a geosynthetic. In this paper, a comprehensive method of analysis is demonstrated via an example which evaluates the stability of a slope reinforced by geosynthetics. All the cases of failure with respect to slope stability are considered via the dual treatment of the geosynthetic elements as weak layers and supporting elements in a limit equilibrium analysis in software.