明挖地铁车站围护结构受力变形监测与数值模拟分析  

Deformation and Force Analysis on Retaining Structure of an Open-excavated Subway Station by Monitoring and Numerical Simulation

作　　者：张明聚[1] 何欢[1] 李春辉[1] 苏智勇[1] 刘晓娟[1] 

机构地区：[1]北京工业大学城市与工程安全减灾省部共建教育部重点实验室,北京100124

出　　处：《北京工业大学学报》2013年第6期875-880,共6页Journal of Beijing University of Technology

基　　金：国家自然科学基金资助项目(50678002)

摘　　要：采用FLAC3D软件对明挖地铁车站围护结构受力变形进行模拟,并将计算结果与现场监测数据进行对比分析.采用所建立的数值模拟方法,对多种预加轴力加载方案中桩身水平变形进行对比分析;研究支撑刚度变化与围护结构变形的关系、围护桩刚度变化与围护结构变形的关系.主要结论有:1)钢支撑预加合理大小的轴力能防止和减少围护结构产生过大的变形,钢支撑预加轴力建议取设计值的80%;2)对变形要求严格的工程中,可加大钢支撑的刚度来减小基坑顶部的水平位移;3)随着围护桩桩径增加,桩身水平变形明显减小,但围护桩直径过大,桩径再增大,控制桩身变形的效果并不明显,设计中从控制基坑变形角度出发,兼顾降低工程造价,选取适当的桩径大小.The simulation of forced deformation on retaining structure of an open-excavated subway station was carried out using the software FLAC3D , and a comparative analysis with field data was accomplished. The established numerical simulation methods are used to analyze the horizontal deformation of pile body in different pre-axial force loading schemes. The relationship between brace stiffness variation and retaining structure deformation and the relationship between variation of fender pile stiffness and retaining structure deformation were studied. Results show that 1 ） steel support pre-applied a reasonable axial force can prevent and reduce the deformation of retaining structure, and a recommended value is 80% of the design value of the axial force; 2） pit top horizontal displacement can be reduced by increasing the rigidity of the steel support in strict deformation requisition; and 3） the pile horizontal deformation will decrease obviously with the increase of fender pile diameter, and the effect will become inconspicuous when the pile diameter is to large. From the perspective of controlling pit deformation, structure designs should select an appropriate size of the pile diameter and take economic benefit into account.

关 键 词：明挖法 地铁车站 数值模拟 现场监测 

分 类 号：TU941[建筑科学—建筑技术科学]