特厚倾斜复合顶板巷道破坏特征与稳定性控制

Study on roadway damage characteristics and stability control of extra-thick inclined compound roof

大倾角特厚复合顶板巷道因其围岩原位强度低、层间黏结力弱,在复杂应力作用下巷道围岩具有非对称破坏特征。结合具体工程实例,采用相似模拟试验、FLAC3D数值模拟和工程测试等方法,分析不规则梯形与拱形巷道在常规对称支护和非对称强力支护条件下围岩应力、位移等变化规律,揭示特厚倾斜复合顶板巷道的非对称破坏机理。研究表明:受岩层赋存特征影响,巷道围岩结构和应力分布的非对称性是造成巷道非对称性破坏的根本原因;复合层状岩层结构面法向约束力减小与钝角部位应力集中直接导致弱面剪切滑移失稳;采用拱形巷道与非对称强力支护能有效改善围岩应力状态、减小围岩变形,提高巷道支护体系的平衡承载能力。

High-angle extra-thick compound roof rock has weak interlayer bonding force and low in-situ strength, and its roadway damage has asymmetric characteristics under the complex stress. Combined with the engineering examples, using similar simulation test, FLAC3 D numerical simulation and engineering test method, the thesis has analyzed the change rule of surrounding rock stress and displacement, etc. of irregular trapezoid and arch roadway, under conditions of conventional symmetric supporting and asymmetric intensive support, and it has also revealed the asymmetric failure mechanism of extra-thick inclined compound roof roadway. It has shown that affected by terrain characteristics, the asymmetric distribution of roadway structure and stress is the primary cause of asymmetric damage of roadway; decreases of compound layered rock level normal binding and stress concentration of obtuse angle parts directly lead to weak shear slip instability; the arched roadway with asymmetric support can effectively improve the stress state of surrounding rock, so as to reduce the deformation of the surrounding rocks, improve the stress state and balance load capacity of surrounding rock supporting system.