基坑开挖对坑内新建地铁车站变形的影响机理及控制措施研究

Research of Influence Mechanism and Control Measures on Deformation of New Metro Station in the Foundation Excavation

城市轨道交通的发展及地下空间的大规模开发建设将不可避免在地铁周边进行深基坑开挖施工,为确保既有结构的安全,有必要对基坑的开挖变形进行计算分析。结合天津某地铁上盖项目基坑工程,分析了基坑回弹及坑内新建地铁站体结构的变形机理,并系统归纳了其影响因素。在此基础上,结合工程实例,有针对性地提出各项坑内地铁站体结构变形控制措施,并采用ABAQUS进行三维有限元建模计算。计算结果表明,本工程基坑设计中所采取的地铁变形控制措施能满足新建地铁车站的保护要求,为同类工程的设计与施工提供了有益的参考。

The development of urban rail traffic and great exploitation of urban underground space will inevitably lead to deep excavation projects around the metro lines. To ensure the safety of the existing metro structures,it is necessary to analysis the deformation caused by excavation. Based on a certain excavation project above subway station in Tianjin,the deformation mechanism of excavation rebound and new metro station in the foundtion pit was analysised,of which factors were summarized systematically. On this basis,combined with practical work,some deformation control messures for the subway station in the foundation pit were pointedly proposed,and the three dimensional FEM modeling and analysis have been carried out by ABAQUS. The results showed that the control measures adopted in the foundation pit design can meet the protection requirement of the new metro station in the pit,which can provide reference for the other similar engineering design and construction.