深基坑施工对邻近桥墩变形的影响  

Influence of deep foundation pit construction on deformation of adjacent bridge pier

作　　者：张鑫磊[1,2] 纪展鹏 高洪梅[1,2] 张盼盼 王志华[1,2] ZHANG Xinlei;JI Zhanpeng;GAO Hongmei;ZHANG Panpan;WANG Zhihua(Research Center of Urban Underground Space,Nanjing Tech University,Nanjing 211816,China;Institute of Geotechnical Engineering,Nanjing Tech University,Nanjing 211816,China)

机构地区：[1]南京工业大学城市地下空间研究中心,南京211816 [2]南京工业大学岩土工程研究所,南京211816

出　　处：《建筑结构》2022年第24期131-137,共7页Building Structure

基　　金：江苏省高校“青蓝工程”中青年学术带头人(QL20210210);江苏省高等学校自然科学研究重大项目(18KJA560002);国家级大学生创新创业训练计划项目(202110291001Z)。

摘　　要：依托南京某深基坑工程,采用有限元软件MIDAS GTS研究深基坑施工对邻近桥墩变形的影响,通过对比现场监测结果与数值模拟结果,验证了数值模型的可靠性。利用已验证的模型,通过数值模拟,分析了各个施工阶段下围护结构及桥墩的变形规律,探讨了深基坑与既有桥墩距离对桥墩变形的影响。结果表明:围护结构的水平变形形态与基坑开挖深度及支撑结构有关,水平变形沿深度方向呈现先增大后减小的规律,最大水平变形量为15.8mm,未超过控制值±30mm,基坑围护结构整体稳定;桥墩承台沉降量最大值为1.5mm,桥墩倾斜率为1.08‰,未超过控制值±2‰,结构安全稳定;基坑周边土体注浆加固及增大桥墩与基坑距离可有效减小桥墩的变形,桥墩变形与桥墩距基坑距离反相关。Based on a deep foundation pit project in Nanjing, the finite element software MIDAS GTS was used to study the influence of deep foundation pit construction on deformation of adjacent bridge pier. The reliability of the numerical model was verified by comparing the field monitoring data with the numerical simulation results. Using the verified model, the deformation law of the retaining structure and bridge pier in each construction stage was analysed by numerical simulation, and the influence of the distance between the deep foundation pit and the existing bridge pier on the deformation of the bridge pier was discussed. The results show that the horizontal deformation form of the retaining structure is related to the excavation depth of the foundation pit and the supporting structure, and horizontal deformation increases first and then decreases along the depth direction. The maximum horizontal deformation is 15.8 mm, which does not exceed control value of ±30 mm. The pit retaining structure of the foundation keeps overall stability. the maximum settlement of pier cap is 1.5 mm, and the inclination rate of the bridge pier is 1.08 ‰, which does not exceed control value of ±2‰. The structure is safe and stable. Grouting reinforcement of soil around the foundation pit and increasing the distance between the bridge pier and the foundation pit can effectively reduce the deformation of the bridge pier, and the deformation of the bridge pier is inversely correlated with the distance between the bridge pier and the foundation pit.

关 键 词：深基坑施工 邻近桥墩 桥墩承台沉降量 桥墩倾斜率 现场监测 数值模拟 

分 类 号：TU443[建筑科学—岩土工程]