城市立体公路隧道施工过程对既有地铁线路影响研究

Study on the Influence of Urban Highway Tunnel Construction on Existing Subway Lines

城市地下交通工程新建隧道穿越既有隧道施工,必然会改变地层中原始应力状态,导致应力重分布,进而使地层产生沉降与变形。以成都某新建下穿隧道上跨既有地铁2号线近接施工为例,通过数值模拟分析了采用分区开挖+隔离支护桩的基坑施工方法对既有地铁2号线结构变形的影响。结果表明,该工法施工引起的地铁隧道位移能满足规范要求,既有地铁隧道受到的荷载减小。

With the rapid development of urban underground engineering,the phenomenon of various new tunnels crossing existing tunnels will be unavoidable.Engineering cases show that the construction of underground engineering will inevitably change the original stress state of the stratum,resulting in stress redistribution,and then causing settlement and deformation of the stratum.Based on the approaching construction process of a new underpass tunnel crossing the Metro Line 2 in Chengdu,this paper analyzes the influence of the isolation pile+partition excavation on the structural deformation of the existing Metro Line 2,and analyzes the changes of the internal force of the metro tunnel structure during the construction process,so as to provide reference for similar approaching construction projects.