Comparison of general limit equilibrium methods for slope stability analysis

Abstract

Slope failure becomes one of the most critical problems in geotechnical works, which resulted in damages to engineering structures, farmlands, and loss of lives. Therefore, slope stability analysis is very important to reduce damages due to slope failure. Soil samples on three selected slope sections were taken and determined the internal friction angle, cohesiveness, and unit weight of soils in the laboratory test. Then, a factor of safety for three slope sections was calculated using different general limit equilibrium methods (GLEMs) under dry and wet slope conditions. The result showed a factor of safety less than one for slope section 1, which is unstable whereas the factor of safety for slope sections 2 and 3 under dry and wet slope conditions is greater than one that is stable. The results of a factor of safety for all GLEMs were computed and compared. Although Corps Engineering 1 and 2, Bishop, and L-KM showed a little factor of safety difference compared to the Sarma method (SM), Spencer method (SPM), and Morgenstern price method (MPM), all methods except the ordinary method, showed similar potential to slope stability analysis. However, SM, MPM, and SPM are good at satisfying all equation of statics and provides a factor of safety vs lambda graph which is impossible in other GLEMs.