软土地区互通立交跨越运营地铁隧道设计分析

Design A nalysis of Interchange Crossing Operation Subway in Soft Soil Area

针对城市互通立交跨越既地铁在施工中的难点,以实际工程为例,采用三维数值模拟方法,分析不同立交布跨设计方案对地铁盾构隧道的影响,通过对地铁盾构隧道变形动态监测数据分析,得出对既有地铁盾构隧道影响最大的是桥梁施工上部结构阶段,隧道变形与桩基净距成反比,与荷载大小成正比;提出桥梁尽量采用跨径小、自重轻的结构,同时采用小直径的桩基,加强监测,采用桩端后注浆控制桩基沉降等优化建议。

In view of the construction difficulty in urban interchange bridges crossing existing operational subway,taking actual project as an example,this paper uses a three-dimensional numerical simulation method to analyze different bridge crossing designs,the impact of bridge construction on subway shield tunnel.Through analysis of the dynamic monitoring data of shield deformation,the construction stage of the upper structure has the greatest impact on the existing subway shield,and the shield tunnel deformation is inversely proportional to the net distance between the piles and directly proportional to the load size.At the same time,the paper puts forward optimization suggestions such as using small-span bridges structure and reducing the structural self-weight,using small-diameter piles,strengthening monitoring,and using pile-end grouting to control pile settlement.