Geophysical observations and numerical modeling constrain mining-induced subsidence and fault reactivation: A case study

Deep mining operations in faulted rock masses are increasingly threatened by fault instability driven by mining-induced stress perturbations. We combine high-resolution microseismic monitoring with three-dimensional numerical modeling to characterize fault slip and subsidence mechanisms at the 8302 working face of the Xinjulong coal mine in China. Full moment tensor inversions of ten representative high-energy seismic (HES) events reveal shear-dominated ruptures around pre-existing faults and tensile-dominated fracturing within the overlying strata. Numerical simulations reproduce the observed spatiotemporal clustering of HES events in areas of elevated and evolving differential stress, delineating progressive fault reactivation during mining. Analysis of asymmetric fault displacements shows subsidence of both the hanging wall and footwall, with greater downward motion on the footwall above the mined-out area. This pattern is atypical for reverse-fault slip and is attributed to stress redistribution following the mining-induced removal of kinematic constraints. Based on these observations, we discuss a targeted blasting strategy to relieve stress in the rock mass and reduce both seismic energy release and event frequency, thereby mitigating the fault-instability hazard. This integrated observational and numerical framework clarifies the interplay among stress redistribution, fault slip, and induced seismicity in deep mining environments and provides a basis for physics-based seismic risk management and hazard reduction.