缓倾斜近距离煤层群开采流固耦合相似模拟覆岩运移规律研究

Overlying strata migration law of gently inclined and close distance coal seam group mining based on similar simulation of fluid solid coupling

为研究缓倾斜近距离煤层群开采覆岩破坏及水动力演变规律,防止开采过程中发生突水灾害,采用理论分析、对比分析、相似模拟等研究手段对工作面是否留设隔水煤柱及含水层加压后突水通道形成进行研究。结果表明:(1)不留设隔水煤柱时,覆岩破坏范围会随L1614、L1615、L1616工作面开采而扩大,顶板重复破坏会形成连通工作面和K3、K4含水层间的导水裂隙;(2)L1814、L1815、L1816工作面分别留设32.9m、47.9m、59.2m宽的隔水煤柱后,导水裂隙只导通了K4含水层;(3)K3含水层加3倍初始水压时,下方离层水静水压力超过下位岩层的极限抗剪强度,击穿下位岩层并与导水裂缝带连通,形成突水通道。

In order to study the overburden failure and hydrodynamic evolution law of gently inclined and close distance coal seam group mining, and prevent water inrush disaster in the mining process, theoretical analysis, comparative analysis, similar simulation and other research methods are used to study whether the water resisting coal pillar is reserved in the working face and the formation of water inrush channel after the aquifer is pressurized. The results show that: without water resisting coal pillar, the damage scope of overburden rock will expand with the mining of L1614,L1615 and L1616 working faces, and the repeated roof failure will form water conducting fissures connecting the working face and K3 and K4 aquifers;after setting 32.9 m, 47.9 m, 59.2 m wide water resisting coal pillars in L1814,L1815 and L1816 working faces respectively, the water conducting fissures only lead through K4 aquifer;When 3 times of the initial water pressure is applied on K3 aquifer, the hydrostatic pressure of the separated layer below exceeds the ultimate shear strength of the lower stratum, which breaks through the lower stratum and connects with the water conducting fracture zone to form a water inrush channel.