软岩巷道围岩剪切滑移破坏机理及控制研究

利用滑移线场理论得到了均质弹塑性围岩发生剪切滑移破坏的滑移线场及包含破坏特征参数的极限载荷计算公式，讨论了围岩内摩擦角、黏聚力以及支护阻力对围岩承载力的影响。研究表明：深部巷道围岩受到开挖应力重分布的影响发生剪切破坏，形成明显的剪切滑移线。圆形巷道围岩破坏区滑移线场为两族仅有旋转方向不同，其他参数都相同且极点在巷道中心的斜交同心对数螺旋线。围岩内摩擦角、黏聚力以及地应力是影响巷道围岩发生剪切滑移破坏的主要影响因素，同时也是巷道稳定性控制的关键。最后根据研究成果对某矿副井发生大变形破坏的原因进行了分析，提出了以?阻剪抗滑?为技术核心的支护方案，收到了良好的效果。

Shear and slip failure mechanism and control of tunnels with weak surrounding rock

The slip-line field of homogeneous elastic-plastic surrounding rock and the ultimate load which containes fracture morphology parameters are obtained by using the slip-line field theory. The effects of friction angle, cohesion and support resistance on the stability of tunnels are discussed. The study shows that with the impact of stress redistribution of excavation, shear failure occurres in the surrounding rock and distinct shear slip-lines are formed. The shear slip-line field of surrounding rock of circular tunnel is composed of two families of oblique crossing concentric logarithmic spirals which have the same pole in the center of the tunnel as other parameters except for different directions of rotation. The friction angle, cohesion of rock and support resistance are the main influential factors of shear slip failure of the surrounding rock and also the key points of controlling the stability of the tunnel. Based on the theoretical analysis, the causes of large scale deformation and failure of some coal mine auxiliary shafts are analyzed. The resistance of shear failure and block slip of the surrounding rock is proposed as the core technology of the support scheme, which is finally proved to be efficient in practice.