An improved dual-strength reduction method of slope stability analysis using Hill Climbing Algorithm

Abstract

How to determine reduction strategy between cohesion (c) and internal friction angle (ϕ) is crucial for slope stability evaluation using the dual-strength reduction method (DSRM). Given that the slope sliding evolution is recognized as a dynamically mechanical system, interaction between sliding mass and sliding bed is governed by minimization of the action, which is consistent with minimum factor of safety of Pan's Extremum Principle. This study introduces an improved dual-strength reduction method by using Hill Climbing Algorithm to determine reduction strategy for the dual-strength parameters. Through employing this approach to analyze the stability of an embankment slope under unsaturated steady seepage, the reduction path of dual-strength parameters is obtained. It is found that the internal friction angle degrades preferentially during the transition from stable state to critical state, followed by the cohesion degradation. The results are in agreement with the rate-and-state friction law. Pore water pressure can reduce frictional resistance, leading to greater degradation of friction angle at critical state. Conversely, the water-rock softening effect can lead to a smaller reduction in the friction angle than in cohesion. This method can provide a new insight into developing dual-strength parameters reduction strategy for the slope stability analysis.