近距离煤层回采巷道合理布置及支护技术研究

Research on reasonable arrangement and support technology of mining roadways in closed coal seams

为了确定炭窑坪矿近距离煤层回采巷道合理布设位置,对上位4号煤层开采底板破坏深度进行理论计算,判定了下位5号煤层位于上位4号煤层开采损伤破坏范围内;采用FLAC^(3D)数值模拟软件对单侧和双侧采空区遗留煤柱底板应力分布特征进行分析,结果表明遗留煤柱下方为应力增高区,外错遗留煤柱10~40 m范围为应力降低区,且外错遗留煤柱10 m时垂直应力和应力集中系数最小,为下位5201工作面回采巷道最佳布设位置。提出采用“锚杆+工字钢+单体柱”的联合支护方案并给出了具体支护参数,现场实测结果表明,回采巷道顶底板和两帮移近量最大值分别为116.94 mm和90.54 mm,巷道围岩控制效果较好。

In order to determine the reasonable location of the short-distance coal mining roadway in Tanyaoping Mine,theoretical calculations were carried out on the floor damage depth of the upper No.4 coal seam,and it was determined that the lower No.5 coal seam was within the mining damage and destruction range of the upper No.4 coal seam;FLAC^(3D) was adopted.The numerical simulation software analyzed the stress distribution characteristics of the coal pillar floor of the single-sided and double-sided mined-out areas.The results showed that the area under the remaining coal pillar was a stress-increasing area,and the 10~40 m range of the left-out coal pillar was a stress-reducing area.The vertical stress and stress concentration coefficient were the smallest when the coal pillars left by the external fault were 10 m,which was the best placement position of the mining roadway in the lower 5201 working face.The combined support scheme of"bolt+I-beam+single column"was proposed and specific support parameters were given.The field test results showed that the maximum values of the roof and floor and the two sides of the mining roadway were 116.94 mm and 90.54 mm,the control effect of the surrounding rock of the roadway was better.