厚煤层采空区下双巷切顶留巷关键技术研究及应用OA

In view of the difficult problem of the surrounding rock stability control of retaining roadway along goaf under goaf with thick coal seams,taking the 9101 working face of Jinrui Coal Mine as the engineering basis,combined with theoretical analysis and on-site monitoring means,the mechanical evolution mechanism of the overburden rock under the goaf is revealed,and methods of roof cutting parameter optimization and collaborative support design are proposed.By constructing mechanical models of overburden rock structures under non roof cutting and roof cutting conditions,combined with the expansion effect of broken rock mass and rock mass failure criteria,calculation methods for key parameters such as roof cutting height(interlayer spacing −0.5 m),roof cutting angle(12°),hole drilling spacing(250 mm)and others are derived,a high-density hole drilling presplitting and pressure relief coupling support system with grouting anchor cables as the core is established,and the anchor cable support density of≥2.11 strands/m is clarified.The engineering actual measurements indicate that after optimization,the cumulative deformation amount of the roof was less than 120 mm,the load peak value of the anchor cable tends to stabilize after reaching 199.6 kN,the growth rate of the convergence quantity of the roadway side is significantly declined,and the gangue movement is effectively controlled,providing a theoretical basis and practical paradigm for the safe maintenance of retaining roadway along goaf in complex goaf.