摘要
地铁车站基坑近接既有构筑物施工时,周边构筑物变形不仅与基坑的开挖深度、开挖方式、施工顺序等因素有关,还与围护结构设计参数、支撑刚度有关。以南京某地铁深基坑邻近既有高架桥为工程背景,通过建立深基坑与高架桥的三维空间模型,探究不同的支护参数和基坑开挖顺序对邻近高架桥墩顶的位移变化规律。研究结果表明:围护结构混凝土强度等级越高,墩顶位移越小,混凝土强度等级变化对邻近高架桥墩顶位移影响不大;排桩等效厚度越大,墩顶位移越小,排桩桩径与桩间距变化对邻近高架桥墩顶位移变形影响较小;第3层钢支撑刚度越大,墩顶位移越小,增大支撑刚度对邻近高架桥墩顶位移控制是有利的;墩顶位移随基坑开挖顺序改变而变化,将6号线车站基坑提至7号线车站基坑前施工,可减小墩顶位移。
When a foundation pit of the subway station to be excavated is close to existing structures,the deformation of the surrounding structures is related not only to the excavation depth of,excavation methods for,construction sequence and other factors of the foundation pit,but also to the design parameters of the retaining structure and the stiffness of supports.With a certain foundation pit of Nanjing Metro close to an existing viaduct as the engineering background,established in the present paper is a 3-D space model for the deep foundation pit and the viaduct in order to explore the effect of different support parameters and excavation sequences of the foundation pit on the displacement change law of the pier top of the adjacent viaduct.The results of our research show that:the higher the concrete strength grade of the retaining structure is,the smaller the displacement of the pier top will be,and the effect of the change in the strength grade of concrete on the displacement of the pier top of the adjacent viaduct is not great;the larger the equivalent thickness of the row piles is,the smaller the displacement of the pier top will be,and the effect of the change in the diameter and spacing of the row piles on the displacement of the pier top of the adjacent viaduct is relatively little;the greater the rigidity of the third layer of steel support is,the smaller the displacement of the pier top will be,and increasing the support stiffness favors controlling the displacement of the pier top of the adjacent viaduct.The displacement of the pier top varies with the change of the excavation sequence of the foundation pit.Advancing the construction of the station foundation pit of Line 6 before that of the station foundation pit of Line 7 can reduce the displacement of the pier top of the adjacent viaduct.
作者
赵雨军
ZHAO Yujun(The Municipal Construction Engineering Co.Ltd.of the 15th Bureau Group of China Railway,Luoyang 471000,China)
出处
《国防交通工程与技术》
2020年第6期61-64,73,77,共6页
Traffic Engineering and Technology for National Defence
基金
中铁十五局集团公司技术开发项目课题(2018B69)。
关键词
地铁
深基坑
高架桥
墩顶位移
敏感性参数
metro
deep foundation pit
viaduct
pier-top displacement
sensitivity parameters
作者简介
赵雨军(1970-),男,高级工程师,主要从事建筑及市政工程施工管理工作。
