急斜煤层群重复采动沿空软岩巷道变形破坏机理

Mechanism analysis on deformation and failure of gob-side entry in soft rock and steep coal seam group with repeated mining operation

急倾煤层沿空软岩巷道变形破坏机理复杂,多次采动影响下巷道维护难度大.利用现场调研实测、物理相似模拟实验和数值模拟分析,对赵家坝急斜煤层群重复采动沿空软岩巷道变形破坏机理进行了深入分析结果表明:赵矿急斜巷道变形破坏是十分复杂的时间、空间问题,即在初次采动阶段:非对称岩体结构及应力分布导致巷道变形失稳;二次扰动阶段:非对称原岩应力释放机理导致巷道变形失稳;三次、四次扰动阶段:拱脚效应与层间压剪变形失稳机理导致巷道变形失稳,为该类型巷道支护形式与参数的选择提供了科学依据.

The deformation and failure mechanism of gob-side entry in soft rock strata and steep coal seam is very complex and hard to be understood. In particular, it is difficult to maintain the entry under the impact of repeated mining operation. Based on the site measurement, physical analogous simulation and numerical simulation, the deformation and failure mechanism of the gob-side entry in Zhaojiaba coal mine is analyzed in this study. The study results show that with the repeated mining disturbance, the entry deformation and failure is a complicate time-space problem. In other word, at the initial excavation stage, the asymmetric rock mass structure and stress distribution cause the entry failure, at the second mining disturbance, the asymmetric in situ stress causes the entry failure, and at the third and fourth mining disturbances, the arch foot effect and press-shear deformation between the rock strata layers result in the entry failure. The study provides a scientific basis for determining the reasonable support form and layout parameters.