A PRE-IE-AFOSM-based approach for the reliability analysis of rock slope stability

To efficiently and accurately assess the stability of the rock slope, a reliability analysis approach based on the Partitioned Rigid Element and Interface Element (PRE-IE) method and the Advanced First-Order Second-Moment (AFOSM) method is proposed. Utilizing the PRE-IE method for effective calculation of tangential and normal forces on potential sliding surfaces, constructing an explicit performance function based on the Mohr–Coulomb criterion. The reliability of the rock slope was calculated using the AFOSM method, with the rock mass unit weight, cohesion, and friction coefficient on structural planes considered as random variables. A typical case study is presented, using results from Monte Carlo Simulation (MCS) as a benchmark to compare the proposed approach with mean-value First-Order Second-Moment(FOSM) and Response Surface Method (RSM), validating its accuracy and efficiency. Conducting a reliability analysis of a rock slope near the reservoir of a large hydropower station provides a practical case study in engineering. The calculation results indicate that the loose structure zone in the shallow surface layer of the slope has a risk of instability, which is consistent with actual observational data, proving the applicability of this approach for evaluating the reliability of rock slopes stability.