摘要
成兰铁路云屯堡隧道为我国在建铁路项目中最长的单洞双线合修山岭隧道,工程地质具有“四极三高”的显著特点:地形切割极为强烈、构造条件极为复杂活跃、岩性条件极为软弱破碎、汶川地震效应极为显著;高地壳应力、高地震烈度、高地质灾害风险。地质瞬息多变,多个隧道均处于严重大变形段落,拱顶塌方、初支侵限等情况时有发生,严重影响现场施工进度,安全风险极高。以6#横洞工区软硬不均围岩为例,通过采用“三台阶八步开挖法”施工,有效地控制了拱顶沉降、侧向收敛等变形,节省材料、循环工时缩短、降低施工及管理成本,开挖空间小、作业面多,施工安全有保障,对类似长大隧道软硬不均围岩施工具有一定的借鉴和指导作用。
The Yuntunpu Tunnel of Chengdu-Lanzhou Railway is the longest mountain tunnel with single-hole double-line under construction project in China.The engineering geology has the obvious eharaeteristics of "four extremes and three heights":extremely strong terrain eutting,extremely complex and active tectonie conditions,extremely weak roek conditions,and extremely significant Wenchuan earthquake effects as well as high crustal stress,high seismic intensity and high geological disaster risks.The geology is transient and changeable.Many tunnels are in severe deformation sections.The collapse of the vault and the initial support invading have occurred from time to time,which seriously affects the progress of the construction on site and has extremely high safety risks.Taking the uneven surrounding rock with soft and hard in the No.6 Hengdong industrial area as an example,by adopting the three-bench eight-step excavation method,the deformation of the vault subsidence and lateral convergence,has been effectively controlled,and the materials have been reduced and circular working hours have been shortened,and the cost from construction and management has been cut down.With small excavation space and many operation surface,the construction safety is guaranteed,it has certain reference and guidance for constructing the uneven surrounding rock in similar long tunnel.
作者
张传安
Zhang Chuanan(China Railway 16th Bureau Group 2nd Engineering Co.Ltd.,Tianjin 300162,China)
出处
《铁道建筑技术》
2019年第1期89-92,共4页
Railway Construction Technology
关键词
四极三高
软硬不均围岩
三台阶八步开挖法
拱顶沉降
侧向收敛
four poles and three heights
soft and hard uneven surrounding rock
three-step eight-step excavation method
vault settlement
lateral convergence
