Deformation mechanisms of open-pit high-steep slopes controlled by a fault: An integrated remote sensing, field investigation and numerical simulation study

The engineering disasters caused by fault structural zones represent a persistent challenge in geotechnical engineering. This study employs an integrated approach, combining multi-temporal remote sensing, field investigation, and numerical simulation, to investigate the deformation mechanisms and stability of an open-pit slope controlled by the F15 fault. The results demonstrate that the collapse of the northern slope results from the combined effect of the internal F15 fault structure and external unloading due to underground mining. Remote sensing imagery reveals a four-stage failure process: initial rock deformation, local landslides, local surface subsidence, and final surface subsidence. Significantly, the F15 structural zone alters the deformation trend of the upper slope, channeling displacement towards the eastern valley, with a maximum simulated displacement of 5.4 cm. The safety factor of the slope, calculated using the strength reduction method, is 1.45, and the potential sliding surface is identified as the F15 structural zone. While the slope is currently stable, the limited safety redundancy and observed local landslides highlight the need for targeted monitoring and reinforcement of the fault zone. This study provides data-supported insights for the prevention and control of geological disasters in similar fault-controlled mining slopes.