基于五图双系数法改进的底板灰岩突水危险性评价——以朱仙庄煤矿为例

Improved Five-Map Double-Coefficient Method for Risk Assessment of Floor Limestone Water Inrush—A Case Study of Zhuxianzhuang Coal Mine

摘要: 为克服传统五图双系数法将底板隔水层视为均质介质、忽略岩性空间非均质性对阻水能力影响的局限性，实现煤层底板灰岩突水危险性的精细化评价，研究提出了一种基于阻水系数赋权的改进五图双系数法。首先，参照《煤炭矿井防治水设计规范》(GB 51070-2014)附录B.2.2中推荐的岩体阻水系数参考值，并结合淮北矿区已有岩体力学参数测试成果，确定不同岩性的绝对阻水系数，选定基准阻水系数并计算相对阻水系数；其次，将各岩层厚度与相对阻水系数加权求和，得到等效有效保护层厚度，进而定义精细化带压系数；最后，以朱仙庄煤矿III1031工作面为工程背景，系统计算底板破坏深度、保护层厚度、有效保护层厚度、太灰含水层水压、传统突水系数及改进带压系数，并开展三级判别与双系数判别。结果表明：III1031工作面底板有效保护层厚度为30.77~52.94 m，平均41.22 m；太灰水压为3.0~5.7 MPa；传统突水系数为0.057~0.177 MPa/m，改进带压系数为0.355~0.451 MPa/m。工作面中部偏南区域为非直通式相对安全区，南北两端为非直通式相对危险区，全工作面不存在直通式突水危险区。改进方法能够更客观地反映底板隔水能力的岩性组合差异，为类似地质条件下带压开采底板突水风险评价提供了新的技术途径。

Abstract: To overcome the limitation of the traditional Five-Chart Dual-Coefficient method, which treats the floor aquifuge as a homogeneous medium and neglects the influence of lithological spatial heterogeneity on water-resistance capacity, and to achieve a refined assessment of coal seam floor limestone water inrush risk, this study proposes an improved Five-Chart Dual-Coefficient method based on water-resistance coefficient weighting. First, referring to the recommended rock mass water-resistance coefficient values in Appendix B.2.2 of the Code for Mine Water Prevention and Control Design (GB 51070-2014), and incorporating existing rock mechanics parameter test results from the Huaibei mining area, the absolute water-resistance coefficients for different lithologies were determined. A benchmark water-resistance coefficient was selected, and relative water-resistance coefficients were calculated accordingly. Second, the thickness of each lithological layer was weighted and summed with its corresponding relative water-resistance coefficient to derive the equivalent effective protective layer thickness, based on which a refined pressurized coefficient was defined. The core innovation of this method lies in transforming the actual heterogeneous rock assemblage into a homogeneous virtual rock group of a single benchmark lithology, while preserving its total hydraulic resistance capacity. This approach enables a spatially continuous characterization of the floor’s water-resistance capability, overcoming the homogenization assumption inherent in the conventional method. Third, taking the III1031 working face in Zhuxianzhuang Coal Mine as the engineering background, the floor failure depth, protective layer thickness, effective protective layer thickness, water pressure of the Taiyuan Formation limestone aquifer, traditional water inrush coefficient, and the improved pressurized coefficient were systematically computed. A three-level discrimination and dual-coefficient discrimination were subsequently conducted to evaluate the water inrush risk across the working face. The results indicate that the effective protective layer thickness of the floor at the III1031 working face ranges from 30.77 m to 52.94 m, with an average of 41.22 m. The Taiyuan limestone water pressure varies between 3.0 MPa and 5.7 MPa. The traditional water inrush coefficient ranges from 0.057 MPa/m to 0.177 MPa/m, while the improved pressurized coefficient ranges from 0.355 MPa/m to 0.451 MPa/m. The central-southern part of the working face is identified as a non-through type relatively safe zone, whereas the northern and southern ends are classified as non-through type relatively dangerous zones. No through-type water inrush dangerous zone exists across the entire working face. The refined method can more objectively reflect the lithological assemblage differences in floor water-resistance capacity, providing a novel technical approach for water inrush risk evaluation in pressurized mining under analogous geological conditions.