Fault Activation and Surrounding-Rock Response in a Deep Gob-Side Entry Crossing a Fault

To investigate the local shear deformation and surrounding-rock response associated with a fault intersecting the roof–side corner of a deep gob-side entry retaining roadway, the F4 fault section of the -12110 working-face gate road in Xiaohezui Coal Mine was taken as the engineering background. Fault-plane stress analysis, numerical simulation, roof-separation monitoring, and engineering application were combined to examine the evolution of fault-interface stress, slip, and adjacent surrounding-rock behavior as the relative position between the working face and the fault changed. The numerical results show that as the working face approaches F4, shear action along the fault plane gradually intensifies, with the peak shear stress increasing from approximately 1.69 MPa to 2.90 MPa. Local regions progressively approach and reach the shear-strength limit, while the high-deformation zone becomes concentrated near the fault–roof–side intersection. After the working face passes the fault, the interface stress enters a redistribution stage, whereas displacement continues to accumulate within the previously formed high-deformation zone, and the adjacent roof–side surrounding rock remains at a relatively high load-bearing level. Field monitoring shows that roof separation initially develops in the shallow strata, subsequently extends into deeper strata, and continues to evolve under mining-induced disturbances, exhibiting a staged deformation pattern broadly consistent with the numerical analysis. Based on the spatial and temporal differences between local fault-mechanical evolution and roof deformation, a surrounding-rock control strategy involving advance support in the pre-fault zone, strengthened confinement during fault crossing, and continuous monitoring in the post-fault zone is proposed. The findings provide a reference for identifying key control sections, determining monitoring timing, and implementing support zoning in deep gob-side entry retaining roadways crossing faults.