关键词: 遗留煤柱 , 围岩控制 , 分区支护 , 不稳定岩层 , 数值模拟

Abstract: Utilizing the 5-2 coal seam working face in the first mining district of Guojiawan Coal Mine as an engineering backdrop, the analysis was conducted on the issue of designing a zonal support method for overlying obliquely intersected coal pillar roadways, which is based on the thickness of unstable strata. Through the application of theoretical analysis, numerical simulations, and on-site engineering practices, the study was conducted to investigate the mechanical structure of surrounding rock and the stability of roadways beneath the remaining obliquely intersected coal pillars. This led to the determination of the principles for designing support zoning and the preferred parameters for support, both of which are based on the thickness of intact rock strata. Besides, through field engineering practices, a zoning support plan for the roadway was determined and subsequently simulated for verification. The research findings indicated that when conditions such as the mining height and stress concentration factor at the upper coal seam working face changed, the thickness of the unstable rock stratum also varied accordingly, displaying a positive correlation. Among these factors, the stress concentration factor had a relatively significant impact on it. As the interlayer spacing decreased and approached the centerline of the coal pillar, the stress concentration factor continually increased, while the distance between supports and the effective length of the roof bolt decreased accordingly. In such circumstances, the support scheme was successively adopted with bolt-cable, full-cable, and shed support. The numerical simulation proved to be feasible and practical, and the field verification demonstrated good control effects. This provided a theoretical basis for studying the support issues of roadways located beneath overlying oblique coal pillars.