大跨度开切眼安全监控与稳定性数值模拟分析

Safety Monitoring and Numerical Simulation on the Stability of Large-span Open-off Cut

为解决大断面煤巷锚杆（索）支护存在的困难，以白羊岭煤矿101开切眼围岩控制工程为研究对象，进行超大断面破碎围岩顶板开切眼支护优化设计与安全监控研究，对锚杆（索）支护理论及巷道的失稳机理进行分析研究。针对101开切眼大跨度、大断面矩形巷道的特点，采用动态信息设计方法，分析巷道围岩稳定性的影响因素，制定101开切眼支护方案。应用大型有限元软件 ANSYS 对开切眼顶帮部在不同锚杆（索）间距、长度、单体支柱个数等支护参数条件下的变形及稳定性进行模拟分析，并对比支护前后巷道稳定性。研究结果表明：101开切眼的合理支护方式为顶板采用锚杆（索）联合支护，锚杆间排距800 mm ×800 mm，锚杆长度为2．0 m，单体液压支柱3根／排。在同类条件下，采用高强度锚杆（索）支护的煤巷，在回采期间的围岩变形量比采用普通锚杆支护少21．3％～42．5％；巷道围岩移近总量比锚喷网支护减少25．6％～43．0％，巷道支护效果收益明显。上述研究成果对大跨度、大断面破碎围岩顶板开切眼支护优化设计及施工提供了可靠依据，具有重要的工程应用价值。

To solve the technical difficulties in anchor bolt （cable）support for coal roadway of large cross section, we optimized and monitored the large-span open-off cut on the roof of broken rockmass in Baiyangling coalmine.We also analyzed the support principle and instability mechanism.In association with dynamic information,we de-signed the support schemes according to the features of large-span and big cross section.Furthermore,we analyzed the factors affecting the roadway stability and employed finite element analysis software ANSYS to simulate the de-formation and stability condition in the presence of different parameters （inclusive of spacing,length,and individu-al prop number of bolt （cable））,and then compared the stability of the roadway before and after supporting.Re-sults suggest that to combine anchor bolt and cable on the roof is reasonable for the researched open-off cut.The spacing of bolt is 800mm ×800mm,the anchor length is 2.0m and the individual hydraulic prop is 3 roots per row. By adopting high strength bolt （cable）support,the deformation of surrounding rock in stoping period is 21.3%-42.5% smaller than using ordinary bolt support,and the total amount of surrounding rock deformation reduces 25.6%-43.0% than by adopting the bolt shotcrete support.The effect of high strength bolt （cable）support is ob-vious.