深圳滨海大道改造工程超宽坑中坑降水与开挖响应实例分析  

Dewatering and Excavation Response of an Ultra-Wide Pit-in-Pit in Binhai Avenue Renovation Project in Shenzhen,China

作　　者：韩辉 王锐松 倪芃芃 HAN Hui;WANG Ruisong;NI Pengpeng(China Railway No.4 Engineering Group Co.,Ltd.,Hefei 230041,Anhui,China;School of Civil Engineering,Sun-Yat sen University,Zhuhai 519082,Guangdong,China)

机构地区：[1]中铁四局集团有限公司,安徽合肥230041 [2]中山大学土木工程学院,广东珠海519082

出　　处：《隧道建设（中英文）》2023年第12期2026-2035,共10页Tunnel Construction

基　　金：国家自然科学基金面上项目(52078506);广东省自然科学基金面上项目(2023A1515012159)。

摘　　要：为探究超宽坑中坑降水与开挖过程中基坑变形和地下水的变化特征,采用实测分析方法对围护结构侧移、地表沉降、周边建筑物沉降及地下水与潮汐水之间的关系进行分析。同时,利用ABAQUS有限元软件建立考虑潮汐补水的三维流固耦合模型,研究基坑降水和开挖过程中地下连续墙的侧移规律,并验证分段降水控制和换撑措施对墙体变形的控制效果。主要结论如下:1)基坑开挖过程中,围护结构最大侧移为29.5 mm,南北墙顶均向坑外侧移,地表沉降最大为29.4 mm,立柱、周边建筑物竖向位移量均小于6.5 mm;2)潮汐补水和降雨导致南北两侧坑外水位降落分别约-1.0 m和-1.5 m;3)在坑中坑降水和开挖深坑阶段,采用分段降水控制和钢支撑换撑使墙体最大侧移减小约29%和21%。Herein,to investigate the characteristics of dewatering,excavation-induced deformation,and groundwater variation in an ultra-wide pit-in-pit in the Binhai avenue renovation project in Shenzhen,China,deflection of retaining structures,settlement of surfaces and surrounding structures,and correlation between groundwater and tidal water are analyzed using a field monitoring method.Moreover,a three-dimensional fluid-solid coupling model is established considering tidal water replenishment using the ABAQUS finite element software to explore the development characteristics of underground diaphragm wall deflections during dewatering and excavation processes.The model validates the control effect of the staged dewatering control method and steel bracing change scheme on wall deformation.The following conclusions are drawn:(1)During the excavation process,the maximum wall deflection is 29.5 mm and the north and south wall tops move outward.Further,the maximum surface settlement is 29.4 mm,and the vertical displacements of columns and surrounding structures are<6.5 mm.(2)Tidal water replenishment and rainfall lead to a water level drop of approximately-1.0 m in the north and-1.5 m in the south outside of the pit.(3)During the dewatering and excavation phases,the staged dewatering control method and steel bracing change scheme reduce the maximum wall deflection by~29%and 21%,respectively.

关 键 词：坑中坑 变形特性 地下水变化 工程实测 有限元分析 

分 类 号：U45[建筑科学—桥梁与隧道工程]