Abstract: In actual highway slope engineering, most slopes are non-homogeneous, resulting in discontinuous internal stress field of the slope so that the classic gradient-based optimization algorithms cannot be used to search the slip surface. On the basis of slip surface searching for homogeneous slopes which is based on the global procedure for slope stability analysis, we propose a smoothing processing method for non-homogeneous slopes. By using this method, both the factor of safety and the vertical coordinates of discrete points on potential slip surface are taken as independent variables, and the factor of safety is regarded as the objective function, with three moment equilibrium equations and convexity on the critical slip surface as constraints. This method has a higher convergence efficiency compared with traditional methods based on limit equilibrium in association with intelligent optimization algorithms. Two typical non-homogeneous slope examples show that this method is reliable. The slip surface searched by this method is consistent with that by other finite element equilibrium methods.

Key words: non-homogeneous slope, global procedure for slope stability analysis, smoothing processing, critical slip surface search