深井大倾角厚煤层沿空掘巷底板冲击机理与防治研究

Research on mechanism and prevention of floor impact of gob-side roadway with large dip angle thick coal seam in deep mine

为了研究深井大倾角厚煤层沿空掘巷底板冲击机理与防治方法,以华丰煤矿14采区工作面工程地质条件为背景,通过现场调研、理论分析、工业性试验、SOS微震监测和钻屑量监测等手段,对1412上巷沿空掘巷防治底板冲击进行了研究。结果表明,围岩水平应力和法向应力越低,存储在底板坚硬岩层中的能量就越小,冲击破坏时对巷道造成的影响就越小。揭示了沿空掘巷底板冲击防治机理,通过改变底板能量积聚和应力环境,可有效消除底板冲击危险性。提出留设5 m负煤柱沿空掘巷防治底板冲击的优化设计方案,并在1412上巷进行工业性试验,微震和钻屑法监测数据均表明有效降低了巷道底板发生冲击的可能性。

In order to study the mechanism and prevention method of floor impact of gob-side roadway with large dip angle thick coal seam in deep mine,taking the engineering geological conditions of the working face in No.14 mining area in Huafeng Coal Mine as the background,through field investigation,theoretical analysis,industrial test,SOS microseismic monitoring and drilling cuttings monitoring,etc.,the prevention and control of floor impact of gob-side roadway in 1412 upper roadway were carried out.The results show that the lower the horizontal stress and normal stress of surrounding rock,the less the energy stored in the hard rock stratum of floor,and the less the impact on roadway when impact damage occurs.The mechanism of floor impact prevention and control in gob-side roadway is revealed,and the risk of floor impact can be effectively eliminated by changing the energy accumulation and stress environment of floor.The optimum design scheme of reserving 5 m negative coal pillar along gob-side roadway to prevent floor impact is put forward,and the industrial test is carried out in 1412 upper roadway.The monitoring data of microseismic and drilling cuttings method show that the possibility of floor impact is effectively reduced.