错层位沿空巷道围岩结构及其卸让压原理

错层位沿空巷道特殊的围岩卸让压结构能够解决常规沿空掘巷在深部开采、坚硬顶板时存在巷道维护困难的问题。对比分析了留煤柱护巷和沿空留(掘)巷围岩结构特征,阐述了影响沿空巷道围岩稳定性的主控因素——侧向基本顶关键块的运移。通过力学分析和实验室实验,研究了错层位巷道侧向基本顶下方卸让压围岩结构体系卸让压的力学机理。研究表明:错层位布置使巷道远离侧向集中应力,实现了侧向支承压力向煤体深部转移的效果,避免了沿空巷道受深部高地应力的影响,实现了自动卸压的效果;矸石-三角煤柱结构通过松散矸石大变形缓冲顶板显著运动动载,通过高承载限侧矸石、高稳定性三角煤柱承担关键块静载;自由空间-碎胀矸石组合结构使坚硬顶板充分回转、降至低位态,实现结构性让压,避免顶板受侧向关键块剧烈运动的影响。

Study on the surrounding rock structure of stagger layout roadway and its pressure release as well as deformation yielding mechanism

The problem of roadway support in deep coal mining or hard roof can be solved by special surrounding rock pressure release of stagger layout roadway. In this paper,the surrounding rock characteristic of gob-side roadways with or without coal pillar were analysed. Then the movement of main roof which has large impact on the stability of surrounding rock of gob-side roadway was discussed. The mechanical mechanism of pressure releasing and deformation yielding of surrounding rock structure system was studied by mechanical analysis and laboratory experiment. Results shows that the stagger layout enables roadway to be away from the stress concentration zone which transfers the pressure and avoids the problem of high ground stress. The gangue pillar structure cushions the dynamic load of falling roof and undertakes the weight of key block. The roof made up by gangue gives enough space for hard roof’s movement which in another way protects the roadway.