石炭-二叠系煤层底板下伏巨厚高承压灰岩岩溶裂隙含水层,多发育隐伏构造,部分构造在垂向上具有较强的导水能力,采掘扰动下,极易引发底板突水。聚焦桌子山煤田下组煤开采,采用资料统计、数据分析、数值模拟和理论计算等手段,分析了奥陶系灰岩岩溶裂隙发育特征、水文地质特征,模拟了断层和陷落柱突水,并评价了下组煤安全开采可行性。研究表明:桌子山煤田奥灰岩岩溶发育受到岩性、地质构造、地形及水文网分布等因素影响明显,裂隙主要位于桌子山组灰岩段,厚度小于100 m,在其上部50 m内岩溶较为发育;桌子山组奥灰含水层的非均质特征表现为平面上富水性不均一和垂向上出水层段不均一,奥灰含水层水位总体呈下降趋势;骆驼山煤矿16^#煤层回采过程中为预防发生F61断层和陷落柱突水,所留设的防水煤柱宽度应不少于60 m和125 m;16^#煤层大部分区域底板奥灰水突水系数大于0.06 MPa/m,属于带压开采危险区。

Karst-fissure aquifers within the Carboniferous-Permian carbonate sequence are typically thick and high-pressure. Concealed structures, especially faults and collapse columns, are widely developed, and some exhibit strong vertical hydraulic connectivity, making coal-floor water-inrush accidents likely under mining disturbance. Centering on the lower group of the Zhuozishan Coalfield, this study integrates data compilation and statistical analysis, hydrogeological characterization, numerical simulation, and theoretical calculations to delineate karst-fracture development and aquifer behavior, simulate water inrush along faults and collapse columns, and evaluate the feasibility of safe extraction in the lower coal group. The results show that: The karst development of Ordovician limestone in Zhuozishan coalfield is obviously affected by lithology, geological structure, topography and distribution of hydrological network, mainly in the Zhuozishan formation limestone with a thickness of less than 100 m, especially in the upper 50 m fractures and small karst are more common. The heterogeneity of the Ordovician aquifer in Zhuozishan Formation is characterized by the uneven water richness in the plane and the uneven vertical discharge interval, and the water level of the Ordovician aquifer is generally decreasing. In order to prevent water inrush of F61 fault and collapse column during mining of 16# coal seam in Luotuoshan coal mine, the width of fault waterproof coal column should be not less than 60 m and 125 m respectively. The water inrush coefficient of Ordovician limestone water on the floor of most areas of 16# coal seam is greater than 0.06 MPa/m, which belongs to the dangerous area of mining with pressure.