极近距离煤层群下层煤工作面巷道合理布置位置数值模拟

澄合百良旭升煤矿开采的两层煤间距很近，下煤层开采巷道布置受上煤层开采影响大。应用FLAC 3D数值软件模拟分析了极近距离煤层群下煤层工作面巷道采用内错、重叠和外错布置形式时巷道的塑性破坏、顶板垂直应力和下沉位移特征。根据模拟结果分析，采用内错布置方式时巷道的破坏范围、巷道顶板应力变化和变形量均相对较小。通过进一步的数值模拟研究，巷道的塑性破坏大小、顶板垂直应力值和下沉位移量在内错8 m内变化不大，而随着内错距离的增大，塑性破坏范围和垂直应力值等也逐渐增大。结合压力传递影响角理论，经计算应力集中在下煤层中的影响范围为4 m。得出了下煤层开采巷道合理布置应采取内错的方式，具体位置参数为内错4~8 m。

Numerical simulation on rational location of roadways at lower seam for ultra-close multiple seam mining

Bailiangxusheng Coal Mine at Chenghe currently extracts two coal seams which are in an ultra-close distance.The mining activities in the upper seam significantly affect the roadway stability in the lower seam.In this paper，the FLAC 3D software was used to analyze the plastic failure，vertical stress and deformation characteristics of roadways at inward location，overlap location and outward location in the lower coal seam.The numerical simulation results show that the plastic failure，vertical stress and deformation value are low at inward location.Further numerical simulation show that the range of plastic failure，the value of vertical stress and the deformation changes little inward location with a distance less than 8 m.Moreover，and the longer distance of inward location，the more obvious of the phenomenon.In combination with the theory of pressure transfer influence angle，the influence scope of the stress concentration is within 4 m on the lower seam.The conclusion is that the rational location of roadways in the lower seam is inward location，and the distance is 4 m to 8 m.