浅埋近距离煤层区段煤柱下双巷布置可行性研究

Research on feasibility of double-roadway layout below coal pillar in shallow and close coal seam

针对神东矿区某煤矿浅埋近距离煤层工作面协调开采时下煤层工作面双巷布置的可行性问题,采用数值模拟、物理模拟及现场实测方法,研究了上覆35 m宽区段煤柱下巷道的变形及塑性区破坏特征。结果表明:随着埋深增加,煤柱下双巷变形量增大,埋深为300 m时巷道顶底板累计移近量达2.5 m,巷道变形破坏严重,且下煤层双巷之间的煤柱塑性区完全贯通,煤柱存在失稳现象;考虑到该矿三盘区实际埋深为100 m左右,此时煤柱下双巷受多次采动影响后的顶底板累计移近量模拟值为180 mm、实测值为32 mm,两帮累计移近量模拟值为118 mm、实测值为24 mm,巷道围岩塑性区破坏范围仅为0.5 m,巷道总体保持良好。研究验证了该矿三盘区特定埋深条件下在区段煤柱下布置双巷是可行的,满足工作面安全高效生产需要。

For the feasibility of double-roadway layout in hypogynous coal seam in A Coal Mine of Shendong mining area when working faces in shallow and close coal seam are synchronously mined,roadway deformation and plastic zone failure characteristics below an overburden 35 m wide coal pillar are researched by use of numerical simulation,physical model and field measurement.The results indicate that the greater the cover depth is,the larger the roadway deformation is.Especially,cumulative displacement between roof and floor reaches 2.5 m with serious roadway deformation when cover depth is 300 m,and plastic zones of coal pillar between the double roadways in hypogynous coal seam completely link up,which shows unstability of the coal pillar.Considering the actual cover depth is only about 100 m in No.3 panel of the mine,the simulated cumulative displacement between roof and floor of roadway below the coal pillar after multi-mining is 180 mm and the actually measured one is 32 mm,the simulated cumulative displacement between two sides is 118 mm and actually measured one is 24 mm,and plastic zone failure scope of roadway surrounding rock is only 0.5 m,which is stable on the whole.The research verifies that double-roadway layout below coal pillar in No.3 panel is feasible in some cover depths to satisfy requirements of safe and efficient production in working face.