复杂条件下隧道围岩变形特征

研究目的:新七道梁隧道是甘肃省在建的开挖断面最大的公路隧道,地质条件复杂。研究复杂条件下长大隧道围岩变形分布规律,可以指导隧道开挖支护设计施工,这也是隧道信息化施工的重要手段。研究方法:在现场布设收敛大量量测断面,并长期监测,对隧道围岩收敛测量数据进行曲线分析。研究结果:结果显示隧道开挖后围岩的变形具有时间相关性和空间相关性。包括3个阶段,即急剧变形阶段、缓慢增长阶段、基本稳定阶段。新七道梁隧道围岩变形具有变形较均匀、收敛速度快、变形小、拱顶下沉较水平收敛变形大的特征,这是地质条件、施工技术、周围环境综合作用的结果。表明隧道区围岩条件较好,自稳定性能强,隧道开挖支护设计施工技术科学合理,支护结构较强。围岩变形分析动态反馈于施工中,取得令人满意的结果。研究结论:地质条件复杂、岩性、空间位置变化频繁地段围岩变形变化大,应引起特别注意,并制定相应施工措施。

DEFORMATION CHARACTERISTIC OF TUNNEL SURROUNDING ROCK UNDER COMPLEX CONDITIONS

Research purpose: Xinqidao liang Tunnel is the largest highway-tunnel cross section in Gansu province, with complicated geological conditions. The distribution pattern of the deformations of the surrounding rock of tunnels under complex conditions is studied, so as to provide guidance for the design and execution of the excavation and reinforcement of tunnels, which is one of the most important aspects of information-aided construction. Research method: A large amount of convergence measurement cross-sections are installed in the job site and long-term monitoring and measurement are executed. This paper analyzed convergence data of surrounding rock in the tunnel and effects. Research result: It is pointed that deformation of surrounding rock has the characters of time pertinence and space pertinence. The deformations of the surrounding rock contain 3 stages: rapid-deforming stage, slow-increasing stage and nearly-stable stage. The deformations of the surrounding rock mass of Xinqidaoliang tunnel has such features as uniform deformation, rapid convergence, small deformation and crown settlement larger than the horizontal convergence. Research conclusion: These deformations are functions of many factors such as geological conditions, technology and ambience. Results indicate that the surrounding rock of the tunnel is good with high self-supporting capability, the design and execution technology of the excavation and reinforcement of the tunnel is scientific and rational and the reinforcement structure is strong. The analysis of rock deformation feeds back construction, and produces satisfactory effects.