富水砂层过河明挖隧道基坑围堰方案比选及结构稳定性分析  

Scheme Comparison and Structure Stability Analysis of Open Cut TunnelFoundation Pit Cofferdam for Water-Rich Sand Layer Crossing

作　　者：刘建华[1] LIU Jianhua(China Railway 18th Bureau Group the Fifth Engineering Co.,Ltd.,Tianjin 300459,China)

机构地区：[1]中铁十八局集团第五工程有限公司,天津300459

出　　处：《国防交通工程与技术》2023年第6期40-44,56,共6页Traffic Engineering and Technology for National Defence

基　　金：中铁十八局集团第五工程有限公司科技研究开发项目(G19-13)。

摘　　要：明挖基坑是基坑工程中的一种常见形式,而围堰是基坑工程中常用的封闭方式,选择合适的围堰施工方案能够降低施工措施费用、简化施工程序、提高施工进度。依托安徽省亳州市某过河隧道工程,利用连续介质有限元软件Plaxis建立计算模型,数值模拟分析结果表明:由于过河隧道穿越砂层深厚、渗透系数大,导致钢板桩围堰受到较大的渗流力作用,容易发生偏移,因此适宜采用充砂模袋作为基坑围堰,延长渗流路径从而有效降低渗流力对基坑开挖的影响。数值模拟所得到的计算结果与实际监测结果差别较小,趋势一致,采用充砂模袋围堰方案可以有效保证基坑开挖的渗流和变形稳定。Open cut foundation pit is a common form of foundation pit engineering,while cofferdam is a commonly used closure method in foundation pit engineering.Choosing a suitable cofferdam construction scheme can reduce the costs of construction measures,simplify construction procedures,and improve construction progress.Based on a certain river-crossing tunnel project in Bozhou City,Anhui Province,a calculation model was established using the finite element software Plaxis for numerical simulation analysis.The results show that due to the deep sand layer and large permeability coefficient of the river-crossing tunnel,the steel sheet pile cofferdam is subjected to large seepage force and is prone to deviation.Therefore,it is suitable to use sand-filled bag cofferdam as the pit cofferdam,which can effectively extend the seepage path and effectively reduce the impact of seepage force on excavation.The calculation results obtained by numerical simulation are similar to the actual monitoring results,and the trend is consistent.The use of sand-filled bag cofferdam scheme can effectively ensure the stability of seepage and deformation during pit excavation.

关 键 词：基坑工程 围堰 钢板桩 充砂模袋 渗流力 

分 类 号：TU473.5[建筑科学—结构工程] U455.45[建筑科学—土工工程]