深部近距离厚煤层开采覆岩结构空间的演化规律与应力分布特征

针对深井近距离煤层回采过程中，煤层工作面及其巷道频繁出现的形变过大、矿压突增问题，以海石湾煤矿近距离煤层开采为参考，采用相似模拟实验与理论计算方法，分别对距离相近的煤层因回采造成的覆岩结构演化、运动及围岩应力变化进行了模拟与分析.研究表明:覆岩中主关键层是否失稳破断对矿压分布的影响重大.在主关键层破断前，近场结构是矿压增量的主要来源，并使矿压具有波动性；当主关键层破断后，远场结构对于近距离各煤层矿压增量均起到主要作用，并使其变化特征具有典型的跳跃性.自下而上逐级传播的覆岩结构演化造成了主关键层的阶段性沉降，对于矿压的跳跃式变化起到了主要作用.研究发现了近距离煤层开采过程中的覆岩演化规律和矿压产生机理，对于采场矿压控制和巷道支护优化具有指导意义.

Evolution and Stress Distribution of Overlying Strata in Deep and Thick Closer Coal Seam

Simulation experiments and theoretical calculations are conducted with reference to Haishiwan Coal Mine to solve such problems as excessive deformation and sudden pressure increase in the coal seam and the roadway during the coal mining process in deep wells. The evolution and movement of the overlying strata structure caused by the mining of the coal seams at similar distances were simulated and analyzed. The results show that whether the main key layer in the overlying strata is unstable or broken has a significant impact on the pressure distribution. Before the main key layer breaks, the near-field structure is the main source of rock pressure increment and volatility. After the main key layer is broken, the far-field structure plays a major role in increasing the pressure of each close coal seam and causing the jumpy increase of pressure. The evolution of the overburden strata that spreads from bottom to top causes the subsidence of the main key layer, which plays a major role in the jumpy change of the mine pressure. The knowledge of the law about overburden rock evolution and the mechanism of rock pressure during the mining of closer coal seams are of guiding significance for the ground pressure control and the optimization of roadway support.