关键词: 近距离煤层, 回采巷道布置, 理论分析, 数值模拟

Abstract: To solve the problems in determining the reasonable position of roadways in the close distance seams，the depth of destroyed floor，the stress distribution in the floor under a coal pillar left in the upper coal，and the reason why roadways are easy to transform and fail under heterogeneous load are studied through numerical simulation and theoretical calculation. The result shows that the maximum depth in the floor caused by the abutment pressure from the upper coal being mined is 25.3 m，which spread to the level of roadway in the close distance seam. The stress distribution in the floor around the pillar has obvious heterogeneous characteristic：the stress-concentrated area lies under coal pillar and concentration degree decreases quickly away from the center of coal pillar. The roadway support structure is subject to overlarge partial tension stress and produces deformation and failure under the heterogeneous load. The change of principal stress is defined to evaluate the heterogeneous degree. Considering that the resource is recycled to the maximum, combined with the stress distribution characteristics of the numerical simulation, an inner stagger distance of 14 m for the roadways in the close distance seams is determined.

Key words: close distance seams, layout of roadway, theoretical analysis, numerical simulation