State Key Laboratory of Water Resource Protection and Utilization in Coal Mining, National Institute of Clean and Low Carbon Energy
Institute of Mine Safety Technology, China Academy of Safety Science and Technology

科学认知煤层采后上覆岩层损伤破断特征是厘清覆岩井上下一体化联动规律及地表非连续变形的前提和基础。采用理论分析、相似模拟等手段并考虑分步开采引起的岩层损伤积累效应,开展上覆岩层损伤破断特征研究。结果表明,煤层上覆低位岩层因分步开采损伤积累效应,岩层悬空部分端部和中部的最大损伤点在推进方向上滞后最大拉应力点的距离分别约为0.3NL0和0.1NL0,低位岩层的初次破断将整体表现为偏“O-X”破断,通过自主研发的三维相似模拟试验平台进行了试验验证。煤层上覆岩层的首次分步暴露均会产生损伤积累效应,从而导致其发生非对称破坏,地表出现偏态下沉是上覆各岩层非对称破断共同叠加的结果。

Scientific understanding of the damage fracture characteristic of overlying strata after coal mining is the premise and foundation for clarifying the integrated linkage law of overlying strata and the discontinuous deformation of the surface. The damage and fracture characteristics of overlying strata were studied using theoretical analysis, similarity simulation, considering the cumulative effect of overlying strata damage caused by step-by-step mining. The results show that due to the damage accumulation effect of step-by-step excavation, the maximum damage point at the end and middle of the suspended part of the strata lagged behind the maximum tensile stress point about 0. 3NL0 and 0. 1NL0, respectively in the advancing direction, and the first fracture of the low rock stratum would be a partial “O-X” fracture. These phenomena were verified by the self-developed three-dimensional similarity simulation experimental platform. The first exposure of overlying strata above coal seam would produce damage accumulation effect, resulting in asymmetric failure. The surface skewed subsidence was caused by the combined action of the asymmetric failure of overlying strata.

煤炭开采水资源保护与利用全国重点实验室项目(SHGF-16-24);国家自然科学基金青年基金项目(52004012)

徐祝贺, 李晓斌, 张国军, 等. 煤层开采上覆岩层损伤破断特征研究 [J]. 煤炭工程, 2023, 55(12): 128-133.