Comparison of FEA and analytical methods for determining stability of a RAP supported MSE wall

Global stability is one of the failure modes that must be analysed for retaining walls. Limit equilibrium analysis of walls using slope stability software tends to result in a factor of safety that is either too high (circular surfaces) or too low (V-shaped non-circular surfaces). Finite element analysis (FEA) of walls provides a better solution but can be time-intensive and expensive. The primary aim of this project is to compare the results of FEA models with a simpler analytical bearing capacity method that uses Meyerhof’s load inclination correction factors. In particular, cases were examined where Rammed Aggregate Pier reinforcing elements (RAPs) support a mechanically stabilised earth (MSE) retaining wall. For this project, several FEA models replicating these cases were created. Geometric parameters included the area ratio of RAP to matrix soil, or “replacement ratio”, and the dimensions of the MSE wall. Each geometric configuration was then iterated over a range of undrained strength for the matri...