Stability Analysis and Optimization Design of Composite Slopes in Open-Pit Mines

Mineral resources play a crucial role in modern construction, and open-pit mining is the primary method for resource extraction. Ensuring slope stability is vital for the normal operation of open-pit mining. This study focuses on an open-pit coal mine in Xilin Gol League, Inner Mongolia, China. Through comprehensive methods such as geological data collection and analysis, field investigation, and UAV mapping, the Slope/W module in GeoStudio software was employed, and the Bishop limit equilibrium method was used to perform a stability analysis on two cross-sections of the composite slope between the mining pit's East Slope and the external dumping site. The results showed that the safety factors for these two sections of the composite slope do not meet the required reserve safety factor. After applying a toe-weighting optimization design, a subsequent stability analysis was conducted, ensuring the stability requirements were met. The main factors affecting the stability of the composite slope were analyzed, including the geotechnical properties, slope rock mass structure, the design distance between the external dumping site and the mining slope, and surface water erosion and seepage. Safety and mitigation recommendations were proposed for other open-pit mines with composite slopes involving external dumping sites and mining slopes.