Slope Stability Analysis of an Earth Dam by Using Limit Equilibrium Method and Finite Element Method

Slope stability analysis is one of the most prominent subject matter in geotechnical engineering. A comparison has been conducted between the methods of limit equilibrium (LE) and finite element (FE) that are commonly used in this study. The study utilizes one LE based software (SLOPE/W) and one FE based software (PLAXIS). The principal difference between these two analyses approaches is that the LE methods are based on the static of equilibrium whereas FE methods utilize the stress‐strain relationship or constitutive law. To fulfil the aims of the study, the LE methods, Ordinary (ODM),  Bishop Simplified (BSM), Janbu (JM) Spencer (SM), Morgenstern-Price (M-P) and Spencer methods are compared to finite element (FE) method by the factor of safety (FOS) obtained for various load combinations. This difference initially due to the distribution of force along the collapse surface. The analysis of FE and LE methods can reveal the main differences in internal force distribution, particularly at the ends of the foot slope, for the surface area. The combination of transerve forces is the reason for this difference, which is not depicted in the LE mothod analysis. The weight of the collapse mass determines the internal forces at the edges.