Abstract:
In order to solve the water hazard risk of suspected collapse column in D3 geophysical exploration of Zouzhuang Coal Mine in Huaibei Coalfield, Anhui Province, it is necessary to find out its spatial morphology and hydrogeological characteristics, and put forward effective treatment plans. A comprehensive approach integrating 3D seismic exploration, surface electrical methods, borehole verification, and pumping tests was employed to determine the spatial morphology, water-conducting properties, and water-rich characteristics of the collapsed column. Based on the Coal Mine Water Prevention and Control Guidelines, a design for waterproof coal (rock) pillars and treatment measures was formulated. The collapsed column exhibits an inverted funnel shape, narrower at the top and wider at the bottom, with a nearly vertical central axis. Its planar form is elliptical, with a long axis of 200 m and a short axis of 110 m, and a development height of approximately 300 m. Borehole investigations revealed multiple fractured zones (
RQD = 40%~66%). Pumping tests indicated a specific yield of
q = 1.368~2.32 L/(s·m) and a permeability coefficient of
K = 1.894~23.52 m/d, suggesting strong water-rich properties and a close hydraulic connection with the Ordovician limestone aquifer. Using dual-model calculations for "along-seam pressure" and "vertical water pressure," the required width of the waterproof coal (rock) pillar was determined to be 85 m. A treatment method was proposed involving the injection of cement and aggregate through surface directional borehole groups to construct a "water-blocking plug" at the Taiyuan Formation’s Fourth Limestone layer, enabling effective drainage and sealing of the nappe limestone water. This study establishes an integrated "investigation-evaluation-treatment" technical framework for preventing and controlling water hazards associated with collapsed columns. It clarifies the developmental characteristics and hydrogeological properties of the D3 collapsed column and proposes targeted treatment measures.