近距离煤层群下行开采底板应力分布规律研究

Study on Floor Stress Distribution in Close Distance Downward Mining Coal Seam

为研究近距离煤层群下行开采下位煤层巷道合理位置,通过建立力学计算模型,推导出底板岩层内应力分量。并结合吴官屯煤业开采实际条件,计算得出上部煤层开采后底板应力状况。结果表明:底板中垂直应力在水平及垂直方向最大影响范围分别达到31m和55m,水平应力在水平及垂直方向最大影响范围分别达到37m和12m,剪切应力在煤柱中心位置下方为0,应力峰值点出现在煤柱边缘,峰值为5.5MPa,该研究可为合理布置下位巷道位置和支护选择提供了依据。

In order to study the reasonable position of the lower coal seam roadway in downward mining of the close-distance coal seam group,the internal stress component of the floor rock layer is derived through establishing the mechanical calculation model.Combined with the actual conditions of Wuguantun Coal Mine,the stress state of the floor after the upper coal seam mining is calculated.The results show that the maximum influence of vertical stress in the horizontal and vertical directions is 31m and 55m respectively,the maximum stress range of horizontal stress and horizontal direction is 37m and 12m respectively,and the shear stress is 0 below the center of the coal pillar.The peak stress point appears at the edge of the coal pillar with a peak value of 5.5MPa.This study can provide a basis for rational arrangement of the lower roadway and support selection.