某地下过街通道上跨轨交一号线的方案研究

Study on the Scheme of an Underpass Upper Crossing Metro Line 1

某地下过街通道上跨既有轨道交通一号区间隧道,其基坑规模较大,深度变化范围大,支护形式多样,基坑围护施工受其主体结构及相邻艺术剧院基坑的影响较大。上跨区域基坑主要采取MJS满堂地基加固、隧道两侧各设置两排钻孔灌注桩、分小块进行基坑抽条开挖、限时回筑等措施,以保证隧道正常运营。运用有限元分析软件PLAXIS 3D进行环境安全性分析,分析结果显示基坑开挖满足地铁隧道保护要求,证明基坑方案可行,也可为类似工程提供参考。

An underpass upper spans the existing tunnel of metro line 1,and its foundation pit has a large scale,a wide range of depth variation,and a variety of supporting forms.The construction of foundation pit enclosure is greatly influenced by its main structure and the adjacent art theater foundation pit.To ensure the normal operation of the tunnel the main measures taken for the foundation pit in the upper span area are:MJS full foundation reinforcement,two rows of bored piles are set on both sides of the tunnel,and the excavation of the foundation pit is divided into small pieces and time-limited backfill is adopted.The finite element analysis software PLAXIS 3D is used to analyze the environmental safety.The analysis results show that the foundation pit excavation meets the requirements of metro tunnel protection,which proves that the foundation pit scheme is feasible and can also provide a reference for similar projects.