多煤层开采终采线外错对冲击地压影响机理研究

Study on Influence Mechanism of Final Mining Line Fault on Rock Burst in Multiple Seam Mining

为研究冲击地压多煤层同时开采终采线外错对冲击地压的影响,以台格庙矿区地质条件为工程背景,采用FLAC3D对下部2-2煤层终采线与上部2-2上煤层终采线的6种不同错距进行数值模拟分析,基于模拟结果和理论分析研究了终采线不同错距煤层应力分布特征以及下部煤层终采线外错对上覆顶板铰接结构的影响。研究表明:当下部煤层终采线外错时,工作面超前应力集中程度增加,同时下部煤层开采可能破坏上部顶板铰接结构,造成变形失稳,动静载荷叠加作用使得下部煤层终采线外错后冲击风险大幅增加,由此提出了优化终采线位置、预裂上部煤层顶板和实施下部煤层卸压3种防治途径。

In order to study the influence of the external fault of the final mining line of the simultaneous mining of two coal seams on the rock burst,taking the geological conditions of Taigemiao mining area as the engineering background,FLAC3D is used to carry out numerical simulation analysis on six different fault spacing of the final mining line of the lower seam 2-2 and the seam 2-2upper.Based on the simulation results and theoretical analysis,the stress distribution characteristics of coal seam under different dislocations of final mining line and the influence of external fault of lower coal seam stop-mining line on the overlying roof structure are studied.The research shows that:when the lower seam stopping line is out of place,the advance stress concentration degree of working face increases,while the lower seam mining damages the stable structure of the upper roof and produces dynamic load.The superposition of dynamic and static load makes the impact risk of the lower seam stopping line out of place increase significantly.Therefore,three prevention and control approaches are put forward:optimizing the stopping line location,precracking the upper seam roof and implementing the lower seam pressure relief.