Abstract: To study the lateral deformation characteristics of the biasing foundation pit enclosure structure of subway station, taking the foundation pit of a subway station for example, a three-dimension numerical simulation model was established by FLAC3D. The influence of e (the distance between building and foundation pit), q (the building load) and h (excavation depth of foundation pit) on the ratio of the maximum lateral displacement on both sides of the retaining structure of the biasing foundation pit in subway station was discussed. Furthermore, the division standard of deviation degree under each factor was established, and the corresponding deformation control measures were put forward. Meanwhile, the sensitivity of each factor was analyzed on the basis of the grey correlation theory to find out the most unfavorable factors. The research indicates that the biasing load caused by the adjacent buildings will greatly increase the lateral displacement of the retaining structure, which is adverse to the safety of the foundation pit. The ratio of the maximum lateral displacement on both sides of the retaining structure has a linear function with the distance “e”, a piecewise linear function with the depth “h”, and a cubic function with the building load “q”. The sensitivity order of influencing factors of unsymmetrical deformation of the retaining structure of the biasing foundation pit of adjacent buildings is as followed: distance between building and foundation pit “e”＞ building load “q”＞excavation depth “h”. The research conclusions can provide references for the design and construction of foundation pit.

Key words: railway engineering, subway station, foundation pit engineering, structure deformation, grey correlation

摘要： 为了研究地铁车站偏压基坑围护结构侧向变形特征，以某地铁车站基坑为工程依托，采用FLAC3D建立三维数值计算模型，探讨了基坑至建筑物距离e、建筑物荷载q及基坑开挖深度h对地铁车站偏压基坑围护结构两侧最大侧移之比的影响，并建立各因素下偏移程度划分标准，提出相应的变形控制措施，同时基于灰色关联理论对各因素的敏感性进行分析，找出最不利影响因素。研究表明:邻建筑物偏压荷载会大幅度增大围护结构侧向位移，不利于基坑安全；围护结构两侧最大侧移之比与距离e呈一次函数关系，与深度h呈分段线性函数关系，与建筑物荷载q呈三次函数关系；邻建筑物偏压基坑围护结构非对称变形的影响因素敏感性排序为基坑至建筑物的距离e>建筑物荷载q>开挖深度h。研究结果对基坑设计和施工等有参考价值。

关键词: 铁道工程, 地铁车站, 基坑工程, 结构变形, 灰色关联