三软煤层巷道围岩变形机理及支护优化技术研究

Research on Surrounding Rock Deformation Mechanism and Support Optimization Technology of Roadway in Three Soft Coal Seam

为了解决15101工作面三软煤层巷道围岩变形破坏的问题,在确定巷道顶底板环境的基础上,对三软煤层巷道围岩侧向支承应力分布及变形机理进行了分析。研究表明:三软煤层巷道侧向应力呈现出应力峰值位置远离煤壁、应力最大值降低、侧向支承应力影响范围扩大等特点,巷道发生变形主要是由于力源集中区应力传递导致帮部剪切滑移破坏和底板挤压夹持破坏;建立了巷道围岩受力力学模型,理论分析了巷道围岩在横向变形和纵向变形的应力表达式,得出巷道变形受到巷道支护强度、底板支承能力、煤体应力传递衰减系数和底板剪切滑移等因素的影响。最后,提出了"控制顶板、加固两帮、强化底板和固定滑移"的巷道围岩控制原则,采取"长预应力锚索+帮部加密锚杆+底板注浆"的综合支护方式对巷道围岩进行了支护优化设计,确保了三软煤层巷道的安全稳定。

In order to solve the problem of surrounding rock deformation and failure in three soft coal seam roadway of 15101 working face, based on the roadway roof and floor environment, the lateral support stress distribution and deformation mechanism of roadway in three soft coal seam are analyzed.The research shows that the lateral stress of roadway in three soft coal seam is far away from the coal wall, the maximum stress is reduced, and the influence range of lateral support stress is expanded. The deformation is mainly due to the shear slip failure of the wall and the clamping failure of the floor caused by the stress transfer in the stress source concentration area. The mechanical model of roadway surrounding rock is established, and the lateral deformation and longitudinal deformation of roadway are analyzed, and the deformation of roadway is affected by the support strength of roadway, the supporting capacity of floor, the attenuation coefficient of coal stress transmission and the shear slip of floor.Finally, the control principle of "controlling roof, strengthening two sides, strengthening floor and fixed sliding" is put forward, and the comprehensive support mode of "long prestressed anchor cable + wall densified anchor + floor grouting" is adopted to optimize the support design of roadway surrounding rock, so as to ensure the stability of three soft coal seam roadway.