大跨度开切眼安全监控与稳定性数值模拟分析

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。

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

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.