浅埋煤层群工作面合理区段煤柱留设研究

Study on section coal pillar of group mining in shallow buried coal seams

为确定浅埋煤层群开采合理的上下煤层区段煤柱布置,减缓下煤层煤柱集中压力和地表裂缝发育,实现环境友好的安全开采,论文以陕北神南矿区柠条塔矿为背景,采用Flac3D分析1^(-2)煤层和2^(-2)煤层工作面同采区段煤柱宽度和不同留设方式的应力和塑性区分布规律,以及不同煤柱错距地表下沉规律。通过物理相似模拟,揭示1^(-2)煤层和2^(-2)煤层区段煤柱不同错距的岩层破断规律。研究得出:1^(-2)煤层合理的煤柱宽度为20 m;下煤层煤柱应力、地表下沉梯度和地表拉裂缝随着煤柱错距的增大而减小,沿倾向煤柱错距达到40 m时下煤层煤柱集中应力和地表拉裂隙明显减弱。同采工作面沿走向错距大于60 m时,地表下沉梯度和地表拉裂隙明显减小。

In order to determine the reasonable section coal pillar layout in shallow coal seam group, reduce the coal pillar concentration pressure and the surface cracks development, and realize the safety and environment friendly mining, this paper takes the Ningtiaota Coal Mine of Shennan mining area in North Shaanxi as background, and through Flac3D simulation method, the proper section coal pillar width, the distribution of stress and plastic zone, and the surface subsidence in different layout of 1^ -2coal seam and 2^-2 coal seam mining face are calculated. Through physical simulation, the strata breaking form of the 1 ^-2 seam and 2 ^-2 seam section coal pillar with different stagger distance are revealed. The result shows that the reasonable coal pillar width is 20 m. The effect of lower coal seam pillar stress concentration and surface subsidence gradient will decrease with the increase of the section coal pillar stagger distance of upper and lower coal seam along the tendency, and reasonable section coal pillar stagger distance should be more than 40 m. When the distance of upper and lower mining face along the strike direction is greater than 60 m, the surface subsidence gradient and surface tensile fracture reduce significantly.