倾斜厚煤层动压巷道变形破坏规律及高预紧力锚杆锚索协同支护技术研究

Research on deformation and failure law of dynamic pressure roadway in inclined thick coal seam and collaborative support technology with high pre-tension anchor bolts and cables

针对庞庞塔煤矿倾斜煤层巷道局部收敛变形过大的问题,以5-1062巷为工程背景,通过理论分析和数值模拟,分析总结了巷道失稳机理和变形破坏的主要原因,探讨了围岩变形对动压的响应机制,揭示了高预紧力锚杆锚索协同支护技术对围岩变形的控制机理,并针对原有支护方式不足提出以高预紧力锚杆锚索协同支护技术为核心的优化方案,结合现场条件进行了工业性试验。研究结果表明:护表面积小、预应力低、锚杆(索)支护不协同是5-1062巷支护效果不佳的主要原因;对于倾斜煤层巷道,垂直动压对两帮的影响大,水平动压对顶板的影响大,与水平动压相比,垂直动压是影响巷道收敛变形的主导因素;高预紧力锚杆锚索协同支护技术能给巷道浅部围岩施加均匀的高预应力,保证围岩处于较为稳定三向应力状态,有效提升围岩的稳定性。现场监测表明,采用支护优化方案后,巷道变形得到有效控制,无锚杆锚索破断现象,局部网兜现象得到抑制,现场支护效果良好,为类似工程地质条件下的煤矿巷道围岩变形控制提供参考。

In response to the problem of excessive local convergence deformation in the inclined coal seam roadway of Pangpangta Coal Mine,with the engineering background of 5-1062 roadway,the instability mechanism and main causes of deformation and failure of the roadway are analysed and summarized through theoretical analysis and numerical simulation.The response mechanism of surrounding rock deformation to dynamic pressure is explored,and the control mechanism of collaborative support technology with high pre-tension anchor bolts and cables on surrounding rock deformation is revealed.In response to the shortcomings of the original support method,an optimization scheme of collaborative support technology with high pre-tension anchor bolts and cables as the core is proposed.Industrial experiments are conducted in combination with on-site conditions.The research results show that small surface area,low prestress,and non coordinated anchor(cable)support are the main reasons for the poor support effect of the 5-1062 roadway;for inclined coal seam roadways,vertical dynamic pressure has a greater impact on the two sides,while horizontal dynamic pressure has a greater impact on the roof.Compared with horizontal dynamic pressure,vertical dynamic pressure is the dominant factor affecting the convergence deformation of the roadway;the high pre-tension collaborative support technology can apply uniform high prestress to the shallow surrounding rock of the roadway,ensuring that the surrounding rock is in a relatively stable three-dimensional stress state and effectively improving the stability of the surrounding rock.On-site monitoring shows that after adopting the optimized support scheme,the deformation of the roadway is effectively controlled,without the phenomenon of anchor bolt and cable breakage,and the local mesh phenomenon is suppressed.The on-site support effect is good,providing reference for the deformation control of surrounding rock in coal mine roadways under similar engineering geological conditions.