残留区段煤柱下近距离煤层回采巷道布置方式研究

Layout of Mining Roadway in Close-Distance Coal Seam Under Residual Section Coal Pillar

残留区段煤柱下近距离煤层回采巷道的布置方式与位置选择十分重要。以青龙煤矿下部煤层21806工作面回采巷道的布置为研究背景,通过理论分析和数值模拟相结合的方法,研究了16^(#)煤层底板的最大破坏深度、残留区段煤柱所承受的载荷大小以及煤柱附近底板岩体的应力分布,利用数值模拟和经验公式确定了21806工作面回采巷道的布置方式与位置。结果表明:16^(#)煤层底板的最大破坏深度为8.6 m,煤柱所承受的均布载荷为10.5 MPa;随着深度的增加,煤柱附近底板岩体垂直应力峰值位置始终位于煤柱中心正下方,水平应力峰值的数量由1个变为2个,位置由煤柱中心正下方逐渐向采空区正下方移动,剪切应力峰值位置变化不大;由不同布置位置的回采巷道掘进后围岩应力特征和经验公式确定21806工作面回采巷道采用内错15 m布置。

The layout and location selection of mining roadway in close-distance coal seam under residual section coal pillar is very important.Taking the layout of mining roadway in 21806 working face of lower coal seam in Qinglong Coal Mine as the research background,through the combination of theoretical analysis and numerical simulation,the maximum failure depth of 16^(#)coal seam floor,the load of residual section coal pillar and the stress distribution of floor rock mass near coal pllar were studied.The layout and location of mining roadway in 21806 working face were determined by numerical simulation and empirical formula.The results are shown as follows.The maximum failure depth of 16^(#)coal seam floor is 8.6 m,and the uniform load of coal pillar is 10.5 MPa.With the increase of depth,the peak position of vertical stress of the floor rock mass near the coal pillar is always located directly below the center of the coal pillar,the number of horizontal stress peaks changes from 1 to 2,and the position gradually moves from the center of the coal pillar directly below the goaf.The peak position of shear stress changes little.According to the stress characteristics of surrounding rock after roadway excavation at different layout positions and the empirical formula,the mining roadway of 21806 working face adopts an inner stagger distance of 15 meters.