同寨隧道进口变形控制技术研究

Research on Deformation Control Technology of Tongzhai Tunnel Entrance

研究目的:同寨隧道进口受高地应力、碳质板岩等地质因素作用,在以I18型钢为主的初期支护参数支护下,施工中出现大变形,拱架扭曲、喷混凝土脱落,严重影响施工安全和进度。本文意在寻找解决大变形的方法,为后续施工提供参考。研究结论:经研究分析得出以下变形控制技术措施:(1)在地应力大变形段采取以抗为主的支护措施,坚持"先强后优化"的原则,支护一次到位,从而达到控制变形的目的;(2)软弱围岩开挖后及时支护,尽早封闭成环,并且适时进行径向注浆,有效加固松动的围岩,改善围岩性能,减少作用于支护结构上的围岩压力,使支护与围岩共同形成受力体系,共同抑制隧道变形的发生;(3)减少开挖对围岩的扰动次数,尽早施作仰拱,严格控制初期支护闭合时间;(4)本文对隧道碳质板岩的控制变形措施,可为类似工程提供借鉴。

Research purposes： Tongzhai tunnel entrance was affected by the same high stress, and other geological factors carbonaceous slate role in the early stages to I18 steel support parameters based support, the construction of large deformation occurs, arch distortion, shotcrete off, seriously affecting construction safety and progress. This paper is finding solutions to large deformation method to provide a reference for the subsequent construction. Research conclusions： （ 1 ） In the stress deformation by the engineering test, take the anti - supporting measures, adhere to the ＂strong first and optimization late＂ principle, support in place at a time, so as to control the deformation. （2） Soft surrounding rock after excavation is timely supported, enclosing to ring as soon as possible, and timely radial grouting to effectively strengthen loose rock, improve the surrounding rock properties, reduce rock pressure effected on the supporting structure, the support and surrounding rock stress system has formed, to restrain the deformation of tunnel. （3） Reduce the times of the excavation, set the inverted arch as early as possible, control the initial support closing time strictly. （4） The control measures of deformation of tunnel carbonaceous slate can provide reference for similar engineering.