同深基坑开挖引起紧邻地铁车站变形特性研究

紧邻已建成地铁车站单侧基坑开挖卸载会引起车站结构不均匀变形,但目前对其变形机制还缺乏系统认识。结合长沙地区某地铁车站工程实例,基于数值方法对同深基坑开挖引起的紧邻地铁车站结构变形发展变化规律进行分析,并讨论有效控制车站结构变形的主要施工措施。研究结果表明,随着开挖深度的增加,地铁车站围护结构水平变形逐渐增大,且增长的幅度逐渐减小;地铁车站主体结构整体刚度较大,对由基坑开挖引起的土体变形传递具有遮拦作用。

Study on Characteristics of Subway Station Deformation Induced by Excavation of Adjacent Deep Foundation Pit

Excavation of foundation pit on one side and removal of load may cause differential deformation of the underground structure of adjacent subway station,and its mechanism has not been systematically understood.With reference to the engineering of a subway station in Changsha,numerical method is employed to analyze the variations of subway station structure deformation induced by excavation of adjacent deep foundation pit,and counter measures are discussed to control the deformation of subway station structure.The results show that with the increase of excavation depth,the horizontal deformation of retaining structure gradually increases,while the amplitude of deformation decreases; and the large integral rigidity of the subway station main structure functions to retain the displacement transfer of soil induced by excavation of foundation pit.