Deformation law and control of surrounding rock of dynamic pressure roadway under coal pillar in close seam group
王伟弓仲标
WANG Wei;GONG Zhongbiao
国能神东煤炭大柳塔煤矿
Surrounding rock deformation and control of dynamic pressure roadway under coal pillar is the main technical problem of close distance coal seam mining. In the mining of close distance coal seams, the stress concentration caused by the remaining coal pillars in the upper coal seam will directly affect the integrity of the surrounding rock of the lower coal seam roadway. In addition, the lateral abutment pressure produced by the mining of adjacent working face will further destroy the stability of roadway surrounding rock under concentrated coal pillar, resulting in roadway side heave, floor heave and even roof subsidence. In this paper, the influence range of overlying coal pillar and the reasonable layout position of roadway under the influence of lateral abutment pressure are analyzed theoretically. The stress distribution law of roadway and the stress distribution law in the range of 20m before and after working face are simulated under different widths of coal pillar. The results show that when the stagger distance between the 22314 return airway and the upper coal pillar is greater than 13.3 m, the influence of the overlying coal pillar can be avoided, but the roadway is still within the influence range of lateral abutment pressure. With the increase of the width of the coal pillar, the vertical stress decreases in the roof and floor of the roadway, and the vertical stress increases in both sides. The vertical stress and shear stress of the return airway within 20 m in front of the working face are asymmetrically distributed along both sides of the roadway. The vertical stress and shear stress on both sides of the roadway are basically symmetrically distributed within 20 m behind the roadway, and the influence of shear stress on the roof of the roadway is greater than that on the side of the roadway. Based on the above analysis, the deformation of the surrounding rock is effectively controlled by optimizing the roadway design, reinforcing the roadway support, constructing large-diameter pressure relief boreholes in the auxiliary side of the roadway in the advanced area and controlling the hanging roof in the return triangle area. The research results have certain theoretical and application significance for the surrounding rock pressure, failure characteristics and stability control of the roadway affected by the concentrated stress and dynamic pressure of the upper coal pillar at different positions of the middle and lower coal seams in the close distance coal seams, which can provide reference for similar mining conditions.
近距离煤层开采煤柱围岩变形数值模拟应力分布
Close-range coal seam mining;coal pillar;deformation of surrounding rock;numerical simulation;stress distribution
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会