Study on the impact of a near-fault underground mining on sinking and drifting engineering in overlying rock strata

A mine features with stable wall rock and thick, deep ore body. To ensure safe mining near the F₃ fault in the 185 m horizon and shaft sinking and drifting in the overlying strata, a 3D numerical calculation model of surface and underground mining is constructed based on the occurrence of ore near the fault, rock lithology of the roof and floor surrounding rocks, geological structure, and the structure of overlying rock strata. FLAC^3D measure is employed to simulate the impact of underground mining on the stability of sinking and driving in overlying rock layers. In addition, the impact of section by section excavation and backfilling on pillar safety and surface stability is calculated and analyzed. The results show that strata movement is a dynamic transfer from bottom to top. The near-fault mining is carried out by skip mining between 10 m wide pillars and mining rooms, which greatly shortens span of the goaf and controls the stope ground pressure near the fault without excessive plastic disturbance of the roof. Limited plastic disturbance in the overlying rock layer has no effect on the shaft engineering. The smooth mining and safe, stable shaft sinking and drifting are achieved. The study provides theoretical reference and technical guidance for safe and efficient deep mining, management of stope ground pressure, and safety and stability control of overlying rock strata.