梅岭关隧道水平岩层稳定性分析与施工技术

摘要

Horizontal stratum, which is frequently encountered in the construction of underground works, possesses the mechanical property of anisotropy and has very complex characteristics of deformation failure. To prevent damage to the jack arch such as separation layer failure at the crown and crown bending and heaving, which are likely to occur during the construction of a large-span tunnel passing through horizontal stratum, a reasonable support scheme should be established. Based on the site investigation, practice, and analysis of geological features and factors affecting the stability of surrounding rock of the Meilingguan tunnel on the Lanzhou-Chongqing railway, corresponding technical measures are addressed.%水平岩层是地下工程中经常遇到的一种岩体,具有明显的各向异性力学性质,其变形破坏特征表现得更为复杂.为了及时预防大跨度隧道穿越水平岩层施工过程中极易出现的平拱、拱顶离层破坏、拱顶弯折内鼓等危害现象,确定合理的支护方案,文章结合新建兰渝铁路梅岭关隧道,根据现场跟踪调查和试验,在对隧道地质特质和影响围岩稳定性因素等进行分析的基础上,提出针对性施工技术措施,并经施工实践证明,避免了隧道坍塌等恶性安全事件的发生,从而有效指导了隧道设计和施工.