新峪矿采空区下近距离巷道矿压特征研究

Ground pressure features of roadway under close range goaf in the Xinyu Mine

  • 摘要: 为研究采空区下近距离巷道的矿压特征,通过现场围岩变形监测分析了回采期间巷道的围岩变形规律,采用数值模拟的方法研究了巷道围岩应力的变化规律。 结果表明:巷道的竖向收敛量是两帮收敛量的2.02~3.09倍;距工作面10m的范围内,是采动影响的剧烈区,两帮在此区域受到的影响更为显著;巷道靠煤柱一侧围岩,竖向应力均呈现出一直增长的趋势,采空区的出现破坏了其下方围岩应力变化曲线的指数函数分布形式;上层采空导致了下层工作面的顶板不完整,支承压力作用明显减弱,影响范围仅为5~10m,相比常规类型巷道,影响范围大大缩小;由于上层煤柱侧向支承压力的存在,帮部岩体易因受压膨胀而破坏,引起顶板整体下沉,采空区渗水会加剧铝质泥岩的底板隆起。

     

    Abstract: To study the ground pressure features of roadway under close range goaf,deformation laws of surrounding rock during mining are analyzed by deformation monitoring.Variations of vertical stress in surrounding rock during mining are obtained by numerical simulation.The results show that the convergence between roof and floor can be 2.02-3.09 times that between two side walls.The intense influence area is 10 m front of working face,where deformation velocity can become fast.The two side walls are influenced more significant in this area.Vertical stress in surrounding rock closed to coal pillar increases when adjacent to the working face.It can be found that the existence of goaf make curves no longer obey exponential function to the base.Working face under goaf has incomplete roof.So effects of abutment pressure decrease.The influence scope of abutment pressure is only 5-10 m,which reduces obviously compared to common roadway.The formation of side abutment pressure in upper coal pillars make a roadway under goaf has a larger deformation,and side walls supports are easy to damage because of a compressive expansion in surrounding rock.Roof sinking caused by the damage of support in side walls,and the seepage from goaf will aggravate the heave of Al mudstones floor.

     

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