以鹤壁四矿2606工作面沿空掘巷为工程研究背景,用 FLAC3 D模拟了煤柱宽度从5 m到15 m变化过程中巷道围岩的主应力差变化规律.结果表明,巷道顶板和回采侧帮主应力差随着围岩深度的增加先增大后减小,在围岩深部趋于定值,巷道顶板影响范围大于回采侧帮;采空侧煤柱主应力差极大值随着煤柱宽度的增大先增大后减小,而极大值位置逐步向巷道围岩深部转移.基于此,支护形式采用新型的斜拉锚索支护体系,具有双向施力、锚固点稳、变形闭锁等优点.矿压观测结果表明,两帮相对移近量为367 mm,顶底板移近量为275 mm,累计离层量为25 mm.
Taking the gobGside entry driving in No.2606 working face in Hebi No.4 Coal Mine as the engineering background,the paper uses FLAC3D to simulate the change law of principal stress difference of roadway surrounding rock with the coal pillar width changing from 5 m to 1 5 m.Results show that the principal stress difference in the roadway roof and mining sides increaG ses at first then decreases with the increase of surrounding rock depth,and it tends to be fixed value in the deep surrounding rock at last;the influenced range in the roadway roof is greater than the mining sides;the maximum principal stress difference of gobGside coal pillar increases at first then decreases with the increase of coal pillar width,and the maximum value position graduG ally transfers to the deep surrounding rock in roadway.Based on these,the new stayedGcable supG port system is adopted,which has the advantages of bidirectional force application,stable anG chorage point and deformation lockout etc.The strataGcontrol observation result indicates that the relative twoGsides convergence is 367mm,roofGtoGfloor convergence is 275mm,and the cumulaG tive bed separation is 25mm.