关山特长隧道高地应力下硬岩大变形规律研究

高地应力下隧道的围岩变形是岩体力学的关键问题之一，甘肃关山隧道埋深较大，在穿越高地应力区域时极易出现围岩失稳、塌方及支护结构大变形等现象。选取隧道典型试验段，通过数值计算及数据监测,对其大变形规律和防控技术进行了研究，进而得到了隧道围岩的变形和应力分布规律。根据分析结果，建议隧道衬砌施工时采用柔性支护的理念进行设计，优化边墙曲率，加大预留变形量，采取径向注浆加固及降低扰动。实践表明，一系列防控措施有效控制了围岩变形，降低了隧道施工风险，可为以后类似工程的设计和施工提供实践借鉴。

Study on large deformation law of hard rock of Guanshan extra-long tunnel under high in-situ stress

Deformation of tunnel surrounding rock under high in-situ stress is one of the key problems of deep rock mechanics. The buried depth of Guanshan tunnel is large, so the instability of surrounding rock, landslides and large deformation of retaining structure would easily occur when it passes through high ground stress area. A typical test section of Guanshan tunnel was selected, then the large deformation law and control technology were studied through data monitoring and numerical calculation, and the deformation and stress distribution laws of the surrounding rock of the tunnel were obtained. Based on the analysis results, a series of prevention and control measures were suggested, such as tunnel lining with the concept of flexible supporting design, optimizing wall curvature, increasing reserve deformation, radial grouting reinforcement and reducing disturbance. The engineering practices indicate that these comprehensive prevention and control measures can effectively control the deformation of surrounding rock, reduce the risk of tunnel construction. 