近距离采空区空侧留巷顶板破坏机理及控制技术研究

Research on the Mechanism of Roof Damage and Control Technology of Air-Side Retaining Tunnel in Close Range Goaf

以新元煤矿3411工作面采空区为例,分析了近距离煤层空侧留巷破坏机理及控制技术,根据弹性理论计算了上煤层采后底板应力分布规律,并通过FLAC^(3D)数值模拟进行验证;计算上煤层后底板破坏深度,基于“块体分散”结构,分析密闭采空区下巷道顶板的破坏过程,在巷道开挖过程中,建议采用设置U型钢伸缩支架、后壁回填等支护方式,通过安装顶板锚杆、回填区顶板加固及采用内回填技术等控制留空巷道围岩。结果表明,预留采空区侧进巷顶板沿采空区最大下沉180mm,两帮最大接近距离328mm,满足工作面作业要求。

Taking the 3411 working face goaf of Xinyuan Coal Mine as an example,the failure mechanism and control technology of close range coal seam goaf were analyzed.The stress distribution law of the upper coal seam after mining was calculated based on elastic theory,and verified through FLAC^(3D) numerical simulation.Calculate the depth of damage to the bottom plate of the coal seam,based on the"block dispersion"structure,analyze the damage process of the roadway roof under the closed goaf.During the excavation process of the roadway,it is recommended to use support methods such as U-shaped steel expansion brackets and backfill on the back wall,and control the surrounding rock of the empty roadway by installing roof anchor rods,reinforcing the backfill area roof,and using internal backfill technology.The results indicate that the maximum subsidence of the roof of the reserved goaf side entry roadway along the goaf is 180 mm,and the maximum proximity distance between the two sides is 328 mm,which meets the requirements of the working face operation.