海域双排钢板桩围堰与明挖基坑变形特性分析

Deformation Characteristics of Double-row Steel Sheet Pile Cofferdam and Open-cut Foundation Pit in Sea Area

以深圳海滨大道一期A段海底隧道工程为背景,针对海域环境双排钢板桩围堰与明挖基坑在施工过程中的变形控制难题,利用PLAXIS数值模拟软件建立有限元模型,通过建立有限元模型,系统的研究了海域双排钢板桩围堰与明挖基坑变形特性及相互影响规律,分析了围堰与基坑距离、基坑内支撑形式及基坑开挖步序等因素对钢板桩围堰变形的影响作用。研究结果表明:基坑开挖将造成围堰较大的水平位移;地连墙最大变形出现在墙体中下部;减小施工平台宽度和增大基坑内支撑刚度等方式可以有效减小钢板桩围堰变形。研究成果可以为类似工程的钢板桩围堰与明挖基坑设计提供参考依据。

In this paper,the subsea tunnel engineering in a section of Shenzhen Haibin Avenue was taken as an example.Focusing on the deformation control problem of double-row steel sheet pile cofferdam and foundation pit in sea area in the process of open-cut construction,the deformation characteristics and influence laws of double-row steel sheet pile cofferdam and open-cut foundation pit in sea area are analyzed systematically by establishing finite element model using the Plaxis numerical simulation software.The influence of the distance between cofferdam and foundation pit,the supporting form in foundation pit and the excavation step of foundation pit on the deformation of steel sheet pile cofferdam are caculated.The research results show that the excavation of the foundation pit will cause a large horizontal displacement of the cofferdam;the maximum deformation of the connecting wall occurs in the middle and lower part of the wall.Reducing the width of the construction platform and increasing the supporting stiffness in the foundation pit can reduce the deformation of the steel sheet pile cofferdam.The research results can provide a reference basis for the design of steel sheet pile cofferdam and open-cut foundation pit in similar projects.