采动软岩大巷围岩破坏演化规律及控制技术

摘要

针对曹村煤矿500水平大巷围岩变形量大和支护结构失效等现象,综合采用理论分析、数值模拟和现场实测的方法分析了大巷反复破坏的关键因素,研究了巷道围岩失稳机理及塑性区演化规律.研究结果表明:相邻工作面采动影响在500水平大巷变形反复破坏中起到了主控作用.受采动应力叠加影响,巷道塑性区由圆形演化为椭圆形,帮部塑性区向深部扩展,而项底板受高应力压缩作用,塑性区回缩.在此基础上采用“治底先治帮”的方案,修复方案实施后,顶底板变形量从1000mm减少至103mm,帮部相对移近量从1200mm减少至113mm.在采动影响下围岩裂隙发育范围虽有所增加,但仍未超出锚杆(索)的锚固范围,巷道围岩变形得到有效控制.%Aiming at the deformation and supporting failure of 500 level roadway in Caocun Coal Mine,the key factors for roadway damage were analyzed,the instability mechanism of roadway surrounding rock and plastic zone evolution law were studied through the comprehensive methods of theoretical analysis,numerical simulation and field measurement.The results showed that,the influence of adjacent mining face played a main role in the deformation and failure of the 500 level roadway.The plastic zone of the roadway changed from circular to oval under the influence of mining stress,and the plastic zone in two sides extended to the deep part.Under the compression effect of high stress,the plastic zone in roof and floor shrank.The scheme of " rib deformation control before floor deformation control" was put forward on this basis.After the implementation,the deformation of the roof and floor reduced from l000mm to 103mm,and the relative displacement of two sides reduced from 1200mm to 113mm.Rock fractured range increased,but not beyond the anchorage range of bolt (cable) under the mining influence,the roadway surrounding rock deformation was effectively controlled.