Abstract: In order to study the combined influence of multiple faults on the stability of the high and steep slope of the open-pit mines, the surface point cloud data was collected by UAV, the fault distribution data was collected by field exploration, and the displacement and plastic zone distribution of the slope un⁃ der several construction conditions were simulated by FLAC3D. The stability of the high and steep slope un⁃ der the joint influence of four faults in Tangya Limestone Mine was analyzed. The stability of Tangya Lime⁃ stone Mine under the joint action of multiple faults is revealed based on the current fault development state and the characteristics of slope instability and failure under the condition of subsequent deep extension min⁃ ing. The results show that: ① The slope failure is mainly concentrated near the fault, and the influence range of the fault on the slope increases with the increase of fault concentration. ② The mechanical cause of slope failure is that faults cut the rock mass, resulting in discontinuous stress transmission between the rock masses, resulting in relative slip and compression failure. ③ The influence of faults on the slope stabil⁃ ity during subsequent deep mining has little change. The maximum displacement of the slope has only in⁃ creased from 50.7 mm to 52.2 mm, and the plastic zone has never been penetrated.

Key words: high and steep slope, stability, fault, numerical simulation