巷道围岩支护的优化与数值模拟

Support optimization and numerical simulation of roadway surrounding rock

针对东荣二矿南二下采区16号煤层的回风下山巷道围岩变形问题,采用理论分析和数值模拟相结合的方法,研究了巷道支护力、围岩体力学参数与塑性破坏能,支护参数与锚固区围岩体力学参数的关系。结果表明:塑性破坏能随着支护力的增加呈先减小后增大的趋势,塑性破坏能在支护力达3.5 MPa时出现极限值;不同支护力下,黏聚力在1.0~3.5 MPa期间,塑性破坏能下降趋势显著,当黏聚力大于3.5 MPa时,塑性破坏能处于较平缓的下降趋势;当内摩擦角小于30°时,支护力越大塑性破坏能越小,当内摩擦角大于30°时,塑性破坏能相差不大;锚杆最优间排距为0.8 m×0.8 m,最优预应力为70 kN,经现场工业测试验证,优化后的支护方案可有效解决巷道变形失稳问题。

This paper is aimed at addressing the surrounding rock deformation of the return air downhill roadway in the 16th coal seam of the south second mining area of Dongrong No.2 Mine.The study involves investigating the relationship between roadway support force,mechanical parameters of surrounding rock and plastic failure energy,and the relationship between support parameters and mechanical parameters of surrounding rock in anchorage zone using the combination of theoretical analysis and numerical simulation.The results show that the plastic failure energy exhibits an initial decrease and subsequent increase with the increase of the supporting force and has a limit value when the supporting force is 3.5 MPa;under different support forces,the plastic failure energy decreases significantly when the cohesion is 1.0-3.5 MPa;in the presence of the cohesion greater than 3.5 MPa,the plastic failure energy is in a relatively gentle downward trend;in the presence of the internal friction angle less than 30°,the greater supporting force means the lower plastic failure energy;in the presence of the internal friction angle greater than 30°,little difference is observed in plastic failure energy;and the optimal row spacing of anchor bolts is 0.8 m×0.8 m,and the optimal prestress is 70 kN.The on-site industrial test verifies the ability of the optimized support scheme to effectively solve the problem of roadway deformation and instability.