近距离下部煤层回采巷道合理位置确定

为研究燕子山矿近距离下部煤层回采巷道的布置，通过理论计算对上部4号煤层4216、4218双侧采空遗留区段煤柱建立力学模型，明晰遗留区段煤柱主应力差在其底板的传递规律；应用FLAC3D数值软件模拟上部区段遗留煤柱在底板不同深度垂直应力、水平应力及主应力差的分布特征，分析了主应力差与应力降低区因素对巷道合理内错距离的影响。结果表明，巷道应布置于低主应力差环境，避开主应力差峰值区域，下煤层水平距离上部煤柱边缘30 m位置时，垂直应力接近原岩应力，平均主应力差值小于1.24 MPa，且主应力差变化率较低；最终确定下煤层工作面回采巷道采用内错30 m布置。现场实践证明，在该错距下巷道围岩变形较小，能够保证矿井安全、高效生产。

Determining reasonable position of roadway for close coal seam

To study the layout of the short-distance thick underlying coal seam stopping roadway in Yanzishan Mine, a mechanical model of the remaining coal pillars in 4216 and 4218 of No. 4 sides of the overlying coal seam through theoretical calculation, and clarified the transfer law of the principal stress difference of the remaining coal pillars in the floor. The author simulated the distribution characteristics of vertical stress, horizontal stress and difference between principal stresses at different depths of floor by using FLAC3D numerical software, and analyzeds the principal stress difference and the stress reducing area roadway within the reasonable factors that influence of the reasonable inner distance. The results show that the roadway layout should avoid the peakand be in the environment of principal stress difference. When the horizontal distance of the lower coal seam is more than 30 m from the edge of the overlying coal pillar, the vertical stress is close to the original rock stress, the average principal stress difference is less than 1.24 MPa, and the principal stress difference change rate is low. Finally, the mining roadway of the working face of the lower coal seam is arranged with an inner stagger distance of 30 m. The field practice shows that the deformation of the surrounding rock is small under the misspacing, which can ensure the safety and efficient production of the mine.