Microseismic response characteristics and stress anomaly zoning in deep outburst-prone coal seams with multi-concealed structures: A case study

Coal and gas outburst disasters represent a significant safety threat in deep coal mining operations, with high stress concentration in concealed geological structures further exacerbating disaster risks. This study focuses on the Ji₁₅–21,050 working face in Pingmei Group's No.8 Mine, employing high-precision microseismic monitoring systems and seismic wave computed tomography (CT) technology to systematically investigate the microseismic response characteristics and dynamic evolution mechanisms of stress anomaly zones in deep coal seams containing multiple concealed structures under high-stress conditions. By analyzing the spatiotemporal distribution of microseismic events during different mining stages, the response relationships within stress field anomalies were elucidated. The Energy Coefficient of Variation (ECV) and logarithmic Energy Index (lg(EI)) were introduced to quantitatively characterize the heterogeneous energy release characteristics during coal-rock fracturing. The results demonstrate that: 1) Faults and concealed structures significantly influence stress field distribution, with microseismic event clustering characteristics showing strong consistency with fault activation processes; 2) Abrupt changes in ECV and lg(EI) values during specific stages can effectively serve as precursors for coal-rock instability risks; 3) Seismic wave CT inversion technology enables visual delineation of stress anomaly zones, verifying the spatial correlation between high-velocity wave zones and gas-enriched regions. This research provides theoretical foundations and technical support for monitoring, early warning, and prevention of coal-rock dynamic disasters in deep coal mines.