Underdip Toppling Failure Mechanism: Case Study Retrospective Analysis and Its Most Determinant Parameters

The underdip toppling failure (UTF) mechanism in rock slopes with a set of discontinuities is analyzed in this study. Various perspectives from the most relevant authors are examined to understand the behavior of this mechanism. The UTF mechanism in rock slopes is explained using field observations from a case study of a mica schist slope validated through a retrospective analysis. An engineering approach is presented to assess the quantitative and qualitative influences of the main parameters on the UTF mechanism based on a numerical method that uses continuous FEM code with Phase 2. The results show that the level of the water table (WT) is the most determinant parameter among the others considered, namely, the discontinuity strength, slope height, state of the natural stresses (K-0), and discontinuity spacing. Finally, recommendations are provided to better understand the parameters that are more influential on the calculation of the factor of safety (FoS) in UTF scenarios.