Hydro-mechanical Modeling of Groundwater-Induced Instability and Dewatering Strategies in Open-Pit Slope Design
摘要
Groundwater plays a critical role in open-pit mining operations, influencing both the design and stability of pit slopes. A comprehensive understanding of groundwater conditions is essential, as inadequate management can adversely affect slope stability and, consequently, the net present value of mining projects. This study evaluates the impact of groundwater on the slope stability of the Sangan iron ore mine through numerical modeling. The findings indicate that while the final-year pit remains stable despite groundwater influences, the tenth-year pit exhibits safety factors below 1.3 in the lower benches and near the pit floor, suggesting potential instability according to the Mohr–Coulomb failure criterion. Further analysis reveals that reducing pore pressure significantly enhances the factor of safety. Consequently, a dewatering system was modeled to mitigate pore pressure and improve pit slope stability. The proposed dewatering strategy involves pumping wells operating at a rate of 80000 m3 per month (30 L/s) over a six-year period, commencing in the fourth year of mining operations, which would effectively lower the water level beneath the pit floor. Validation of the numerical modeling results confirms their reliability and applicability for predicting groundwater flow and assessing slope stability in similar mining contexts.