特厚煤层掘进面围岩能量积聚特征及诱冲机制研究

以新疆硫磺沟煤矿特厚煤层掘进工作面为工程背景,采用现场调研、岩石力学试验和理论分析等方法,对特厚煤层掘进面围岩能量积聚特征及其诱冲机制进行了研究。研究认为：①根据硫磺沟煤矿9-15煤层与岩层的岩石力学试验结果,埋深在100~1000 m时,煤、岩层的能量密度与埋深成正比,煤层与岩层的能量密度比值为1.8~2.3,平均为2.1;②相同深度条件下特厚煤层掘进工作面围岩积聚弹性能远大于薄及中厚煤层,其积聚高弹性能的围岩结构是特厚煤层掘进面更容易发生冲击地压和冲击地压灾害更严重的原因之一;③掘进巷道影响范围内围岩积聚弹性能与煤层厚度和巷道半径成正比,且在同等巷道半径条件下,煤层厚度越大,巷道围岩积聚弹性能越大,当巷道半径为3.0 m时,围岩积聚的弹性能分别为巷道半径为2.5 m和2.0 m时围岩积聚弹性能的1.4倍和2.0倍;④提出的考虑煤层厚度和煤层冲击倾向性的冲击危险性评价方法比当前冲击危险性评价方法更加科学合理,评价结果也更符合现场实际情况。研究结果对特厚煤层掘进工作面冲击地压防治具有一定的借鉴意义。

Energy accumulation characteristics and rockburst mechanism of surrounding rock at heading face of extra-thick coal seam

Taking the extra-thick coal seam heading face in Liuhuanggou Coal Mine as the engineering background, the energy accumulation characteristics and rockburst mechanism of the surrounding rock at heading face of extra-thick coal seam are studied using field investigation, expriment of rock mechanics and theoretical analysis. The following results are obtained: (1) According to the exprimental results of rock mechanics of 9-15 coal seam and rock in Liuhuanggou Coal Mine, when the burial depth is between 100 and 1000 m, the energy density of coal and rock is proportional to the burial depth, and the energy density ratio of coal to rock is between 1.8 and 2.3. (2) Under the same depth conditions, the elastic energy accumulation of the surrounding rock at heading face of extra-thick coal seam is much larger than that of thin and medium-thick coal seam, and the structure of the surrounding rock with high elastic energy accumulation is one of the reasons that the heading face of the extra-thick coal seam is more prone to rockburst. (3) The accumulated elastic energy of the surrounding rock is proportional to the thickness of coal seam and the radius of roadway within the influence range of tunneling. Under the same radius of roadway, the greater the thickness of coal seam, the greater the accumulated elastic energy of the surrounding rock. When the radius of roadway is 3.0 m, the accumulated elastic energy of the surrounding rock is 1.4 times and 2.0 times that of the roadway radius when it is 2.5 and 2.0 m. (4) An evaluation method for impact hazard considering thickness and impact tendency of coal seam is proposed. This method is more scientific and reasonable than the current evaluation method for impact hazard, and the evaluated results are more in line with the actual situations. The research results can be used for reference in the prevention and control of rockburst at the heading face of the extra-thick coal seam.