摘要
新建隧道与已有隧道在平面上相交时,通常需要在垂直方向上选择上跨或下穿的施工方案。其中,下穿已有隧道的暗挖施工尤其复杂,对既有隧道的影响较大。如果开挖方法和支护措施选择不当,可能导致已有隧道发生沉降变形,甚至危及运营安全。尤其是在下穿铁路隧道时,对轨道沉降的要求非常严格,不得超过2 mm。因此,控制既有隧道的沉降变形至关重要,这就需要选择适当的开挖工法和有效的超前支护措施,以确保既有铁路隧道的安全。在实际工程中,采用非爆破开挖、双侧壁导坑法和Φ299超前大管棚技术下穿既有铁路隧道,对既有铁路未造成不良影响,同时降低了暗挖作业的风险。这为类似的下穿暗挖工程提供了宝贵的经验和借鉴。
When a new tunnel intersects with an existing tunnel in a plane,the construction scheme of overpassing or underpassing in the vertical direction is typically chosen.Among them,the underground excavation construction beneath an existing tunnel is particularly complex and has a significant impact on the existing tunnel.Improper selection of excavation methods and support measures may lead to settlement and deformation of the existing tunnel,even endangering operational safety.Especially when underpassing a railway tunnel,the requirements for track settlement are very strict,not exceeding 2 mm.Therefore,controlling the settlement and deformation of the existing tunnel is crucial,which necessitates the selection of appropriate excavation methods and effective advanced support measures to ensure the safety of the existing railway tunnel.In practical engineering,the use of non-blasting excavation,double-side heading method,andΦ299 large-diameter pipe roof technology for underpassing existing railway tunnels has not caused adverse effects on the existing railway and has reduced the risks of underground excavation operations.This provides valuable experience and reference for similar underground excavation projects.
作者
李友武
张基伟
江潮
陈志龙
LI Youwu;ZHANG Jiwei;JIANG Chao;CHEN Zhilong
出处
《重庆建筑》
2024年第S01期102-104,共3页
Chongqing Architecture
关键词
小净距
下穿
既有铁路隧道
大管棚
Small Clearance
Underpassing
Existing Railway Tunnel
Large-diameter Pipe Roof
