Study on the Spatiotemporal Evolution Characteristics of Reverse Fault Reactivation Induced by Mining Disturbance

Deep coal mining often faces the dual challenges of high ground stress and complex geological structures. Mininginduced fault activation is a key factor leading to rockburst and water inrush disasters. This study systematically investigates the spatiotemporal activation and evolution characteristics of reverse faults with different dip angles under the disturbance caused by extraction in the hanging wall and footwall,using a combination of theoretical analysis,numerical simulation applying COMSOL Multiphysics,and physical experiments with similar material. Theoretical analysis reveals the controlling effect of fault dip on the distribution of normal and shear stresses. Numerical simulation results indicate a negative correlation between fault activation initiation time and dip angle:As the dip angle decreases,the mining disturbance is more likely to reach the fault zone. The degree of activation is positively correlated with the dip angle,with higher-angle faults showing more intense activation. In terms of spatial evolution,during hanging wall extraction,the lower end of the fault is first damaged and extends upward,easily inducing floor water inrush and rockburst. During footwall extraction,the upper end is first activated and extends downward,increasing the risk of roof collapse. Similar material experiments confirmed the staged upward propagation of fault activation,with stress and displacement monitoring data closely matching the conclusions of the numerical simulations. This research systematically clarifies the intrinsic relationships among mining-induced stress paths, fault dip angles, and activation patterns, which provides reliable theoretical support and engineering guidance for zoned disaster prevention and early warning of fault-related hazards in deep mines.