Qiang Xubo, Li Ji, Wu Yongping, Chen Chaosen, Dong Jihui
School of Energy, Xi'an University of Science and Technology, Xi'an, 710054, China.
Key Laboratory of Western Mine and Hazard Prevention, Ministry of education, Xi'an, 710054, China.
Sci Rep. 2025 Mar 10;15(1):8212. doi: 10.1038/s41598-025-88953-x.
In the Guxu mining area, the mining of thin coal seams is complicated by the unknown migration structure of the roof overburden and severe mine pressure. Based on this, taking the 1599 working face as the research background, and using a method that combines theory with simulation, starting from the structural fracture of roof overburden rock in thin coal seams, the roof failure characteristics during the mining process are studied, and the roof caving shape and stress distribution characteristics under the influence of mining speed are studied is explored. The research results show that a cantilever beam with a short length forms in the overburden rock of the soft bedrock roof during thin coal seams mining. The roof strata 2,5 and 10 of the 1599 working face control the local overburden activity respectively. After fracture, the pressure increases obviously, and with the collapse of the upper strata controlled by it, the pressure phenomenon occurs in the working face. For thin coal seams, the peak value of supporting stress is slightly smaller than that of medium-thick coal seams, but the peak point of supporting stress is closer to the coal wall. When the advancing speed increases, the length of the cantilever beam will increase, the maximum stress concentration factor and the advance influence range will also increase, but the peak value will shift to the deep part. Therefore, the rapid advance will make the front high stress area away from the working face, and the slow advance will cause the roof overburden pressure relief time to become longer. For the composite bearing layer structure, the acceleration of the advancing speed will cause the bearing performance of the lower bearing layer to be weakened and the bearing performance of the upper bearing layer to be enhanced.
在古叙矿区，薄煤层开采因顶板覆岩迁移结构不明和矿山压力大而变得复杂。基于此，以1599工作面为研究背景，采用理论与模拟相结合的方法，从薄煤层顶板覆岩结构破坏入手，研究开采过程中顶板破坏特征，探讨开采速度影响下顶板冒落形态及应力分布特征。研究结果表明，薄煤层开采时软基岩顶板覆岩中形成短梁悬臂梁结构。1599工作面的2、5、10号顶板岩层分别控制着局部覆岩活动。断裂后压力明显增大，随着其控制的上层岩层垮落，工作面出现压力现象。对于薄煤层，支承压力峰值略小于中厚煤层，但支承压力峰值点更靠近煤壁。推进速度增加时，悬臂梁长度增加，最大应力集中系数和超前影响范围也增大，但峰值向深部转移。因此，快速推进将使前方高应力区远离工作面，推进速度慢将导致顶板覆岩压力释放时间变长。对于复合承载层结构，推进速度加快会使下部承载层承载性能减弱，上部承载层承载性能增强。
