Evaluation of 3D slope stability based on the minimum potential energy principle

Based on the minimum potential energy principle, a novel method is proposed to determine the global sliding direction (GSD), the critical slip surface and the corresponding safety factor (SF) of three-dimensional (3D) slopes with arbitrary-shaped slip surface. The resistance direction at one point on the failure surface is determined based on the relationship between the mobilized shear strength and the virtual displacement which minimizes the total potential energy of failure mass system. The GSD is considered to be the opposite to the composition of resistance on failure surface. Meanwhile, the critical slip surface of 3D slope is generated by two random curves with 8 parameters. Three benchmark slopes and a slope from practice engineering are analyzed to test the validity and accuracy of the present model. The results from the developed method match well with the classical solutions, and the obtained SFs demonstrate that some factors (e.g., local surcharge, composite failure surface, slope geometry and so on) can cause slope instability and failure. The location of critical slip surface and the SF provided by the present method are in good agreement with other solutions. Finally, the influence of failure body volume, shear strength parameters, unit weight, slope angle, surcharge and slope height on the GSD is revealed. This study provides a useful guideline for landslide prediction and reinforcement management in slope engineering.