Stability Analysis of Geosynthetic-Reinforced Slopes Considering Multiple Potential Failure Mechanisms Based on the Upper Bound Theorem

The upper bound theorem (UBT) is widely used in the stability analysis of geosynthetic-reinforced slopes (GRSs). However, the existing research seldom considers multiple potential failure mechanisms when using the UBT to design GRSs. First, based on the upper bound theorem of limit analysis, considering multiple failure modes of GRSs, a translation slicing mechanism was constructed. The implicit equation aiming at the safety factor of GRSs was derived, and a simple and effective discrete iteration method was proposed. Second, the rationality of the method proposed in the paper was verified by comparing the existing examples and calculation methods of GRSs. The results showed that the method can consider multiple potential failure modes of GRSs and accurately determine the critical slip surface and minimum safety factor. Finally, the method examined the influences of soil mechanical parameters, reinforcement distribution patterns, and geosynthetic-reinforcement parameters on the critical failure mechanisms and corresponding minimum safety factors. The results showed that when the multiple potential failure mechanisms of GRSs are fully considered, the critical slip surface may not only be sheared from the slope toe for different distribution patterns. It further showed that it is necessary to consider multiple potential failure mechanisms in the design of GRSs. The interval of external critical failure of GRSs increased with the increase of soil cohesion and decreased with the increase of slope angle and internal friction angle. The interval of the internal critical failure of GRSs increased with the increase of slope angle and internal friction angle. The research results provide a novel idea and theoretical support for the stability calculation of GRSs.