Slope stability has always been a key technical concern in the safe operation of open-pit mines. With the rapid advancement of computer technology, numerical simulation methods have increasingly replaced traditional qualitative approaches, providing a more quantitative means of analysis. This study focuses on the marble slope on the west side of the south mining pit at the Yunnan Diantan Iron Mine. Based on experimental data and parameter calculations, a three-dimensional model was constructed using Rhino software. Slope stability was then analyzed and compared using the three-dimensional finite difference method (FDM) via FLAC3D and the discrete element method (DEM) via 3DEC. The results indicate that the FDM simulation predominantly reveals features of typical push-pull or traction-type landslides, failing to capture the sudden, brittle failure often observed in rock collapses. In contrast, the DEM simulation better replicates the stepwise toppling behavior of rock slope failure, clearly demonstrating brittle fracture characteristics. Overall, DEM more effectively reflects the displacement and deformation behavior of rock slopes, produces less theoretical error, and yields simulation results that more closely align with actual mine conditions.
