大倾角巨厚煤层水平分段开采冲击地压机理及其预警方法

Xinjiang is rich in coal resources, with the predictive reserves accounting for about 40% of Chinese total reserves, gradually becoming one of the most significant energy replace area and the strategic energy reserve area of China. However, there were many cases of rock burst accident during the mining process at a part of large inclined angle thick coal seam in Xinjiang, which is seriously detrimental to mine safety and production. Through the studying of overburden breakage characteristics and caving laws at horizontal section caving face of large inclined angle thick coal seam via laboratory physical simulation, the broken rotary path of the key rock is revealed and occurrence location together with the precursory information of the rock burst is captured. Meanwhile, by using UDEC software, the characteristics of stress around the working face，including the high stress region and its changes，are simulated. The time-space effect and the dynamic evolution law of overlying rocks are studied. Finally, in accordance with the rock fracture mechanics and vibration theory, the mechanical model of surrounding rock at horizontal sublevel caving face in large inclined angle thick coal seam was established. Then the dynamic load characteristics of key roof rock was analysed and the causing mechanism of rock burst disaster and its main controlling factors was revealed. Based on the above, the early warning methods combining with multiple factors and index were put forward. Relying on SOS microseismic monitoring system, early warning and prevention control system to prevent rock burst of working face was established. This Research intended to provide a theoretical basis and reference for safety mining of large inclined angle thick coal seam with horizontal sublevel in Xinjiang.

新疆煤炭资源丰富，预测储量约占全国40%，已成为我国重要的能源接替区和战略能源储备区。疆内赋存的大倾角巨厚煤层，在开采过程中已出现多起冲击地压事故，给煤矿安全生产带来很大危害。采用实验室物理模拟研究新疆大倾角巨厚煤层水平分段开采工作面覆岩破断垮冒特征和矿压规律，揭示关键岩块的破断回转运移轨迹，捕捉冲击地压发生的震源位置和前兆信息。采用UDEC软件模拟分析回采工作面四周围岩应力场分布特征，高应力分布区域及其变迁情况，研究覆岩破断时空效应和动态演化规律。最后采用岩石断裂力学、矿山震动学等理论建立大倾角巨厚煤层水平分段开采工作面围岩结构力学模型，分析顶板关键岩块受力聚能、断裂回转突变释能的动载特性，揭示其冲击地压致灾机理及其主控因素。在此基础上，提出多因素多指标相结合的预警方法，建立基于SOS微震监测系统的防冲开采预警布控体系。课题研究拟为新疆大倾角巨厚煤层防冲安全开采提供一定的理论依据和参考。

课题针对新疆地区大倾角巨厚煤层开采冲击地压的发生机理和监测方法，采用实验室物理模拟研究了大倾角巨厚煤层水平分段开采工作面覆岩破断垮冒特征和矿压规律，揭示了关键岩块的破断回转运移轨迹，捕捉到冲击地压发生的震源位置和前兆信息；采用数值模拟分析了回采工作面四周围岩应力场分布特征，高应力分布区域及其变迁情况，研究了覆岩破断时空效应和动态演化规律。最后采用岩石断裂力学、矿山震动学等理论建立大倾角巨厚煤层水平分段开采工作面围岩结构力学模型，分析了顶板关键岩块受力聚能、断裂回转突变释能的动载特性，揭示其冲击地压致灾机理及其主控因素。研究结果表明：（1）煤层开采时，由于采动影响，煤层间坚硬岩层出现应力集中现象，其破断时释放的高能量是诱发冲击地压的主要因素。（2）倾角对煤岩层组合结构力学性能影响较大。煤层倾角越大，煤岩层失稳时破坏越严重，释放的能量越大，冲击特征越明显。（3）基于大倾角巨厚煤层水平分段开采岩层运移规律，系统地提出了与之对应的冲击地压预警方法，建立了基于SOS微震监测系统的防冲开采预警布控体系。研究成果可对此类矿井冲击地压的防治和预测提供理论依据和实践参考。