Comparative Analysis of Slope Stability using Finite Element Method (FEM) and Limit Equilibrium Method (LEM)

The stability analysis of slopes is crucial for designing appropriate slope stabilisation methods based on the physical and engineering properties of the soil in the slope area. Slope stability is typically evaluated using the factor of safety (FOS) determined through the Limit Equilibrium Method (LEM). However, the Finite Element Method (FEM) has gained significant attention in geotechnical engineering for conducting comprehensive numerical slope stability analyses. By employing mathematical models and computational algorithms, engineers can simulate slope behaviour and predict stability more accurately and efficiently than traditional methods. Thus, this paper aims to analyse the FOS of slopes and identify the critical slip surface using the LEM and FEM performed by computer software. Two slope profiles were analysed using GEO5 for LEM and PLAXIS 2D for FEM. The findings were compared and discussed. The results show that the FEM generally yields higher FOS values, while the LEM provides slightly lower values. The shapes and locations of the critical slip circles are almost identical for each analysis and method. Overall, this comparative study is crucial in ensuring the validity of the performed analysis by utilising computer software to expedite the analysis and design of the suitable slope stabilisation method.