近距离采空区下特厚煤层采准巷道合理布置

Study on Reasonable Layout of Mining Roadway for Large Thickness Coal Seam in Near Goaf

为了解决煤柱下煤层开采所遇到的回采巷道合理布置问题,以山西某矿为工程背景,采用力学分析与数值计算的手段对上煤层开采后底板破坏深度、煤柱下方集中应力分布及巷道塑性破坏特征进行研究。结果表明:3^#煤层开采底板最大破坏深度为6.2 m,对5^#煤层开采影响较小;遗留煤柱造成的垂直与水平应力强度及分布范围随底板深度的增加而衰减,剪应力则反之,且深度超过12 m后应力变化趋于稳定,根据摩尔-库伦理论巷道重叠布置时垂直与水平应力差值较小,受不均衡力影响小;以模拟结果论证理论,巷道外错布置时塑性区最大,重叠次之,内错最小,并考虑资源浪费与经济等因素,选择重叠布置方式。

In order to solve the problem of reasonable layout of stoping roadway in coal seam mining under coal pillars, the failure depth of floor, distribution of concentrated stress under coal pillars and plastic failure characteristics of roadway were studied by means of mechanical analysis and numerical calculation in a coal mine in Shanxi province. The results show that the maximum damage depth of floor of No.3 coal seam is 6.2 m, which has little influence on No.5 coal seam mining. The intensity and distribution range of vertical and horizontal stress caused by the left coal pillar attenuates with the increase of floor depth, while the shear stress decreases, and the stress changes tend to be stable after the depth exceeds 12 m. When the roadway is superimposed according to the Molar-Coulomb theory,the difference between vertical and horizontal stress is small, and the influence of unbalanced force is small. The simulation results demonstrate the theory that the plastic zone is the largest when the roadway is out of alignment, followed by overlap, and the inner error is the smallest.