长沙理工大学学报（自然科学版）2025，Vol.22Issue(2)：61-77,17.DOI:10.19951/j.cnki.1672-9331.20241228001
围堰基坑的水盆效应及其影响机制
Water basin effect and influencing mechanism of cofferdam foundation pit
摘要
Abstract
[Purposes]This paper aims to explore the single-bottom and double-bottom water basin effect and its influencing mechanism of steel pipe pile cofferdam in underwater sand layers.[Methods]The water basin effect problem of building foundation pits was transformed into that of cofferdam foundation pits,and the expressions on the force and deformation of the sealing bottom under the action of single-bottom and double-bottom water basin effects were theoretically derived.The action principle of the water basin effect in cofferdam foundation pits was deeply studied.Based on the foundation pit project of the 6#pier steel pipe pile cofferdam of the Jingwei Bridge for road-rail traffic on Xi'an Metro Line 10,the fast lagrangian analysis of continua 3D(FLAC3D)software was used to perform hydrologic-mechanical coupling on the whole precipitation construction process of the cofferdam.According to the temporal and spatial evolution of the horizontal deformation of steel pipe piles during the precipitation construction of the cofferdam,the influence of the distribution and permeability characteristics of thin soil interlayer in the sand layer,as well as the relative position of thin soil interlayer,steel pipe piles,and sealing bottom concrete on the horizontal deformation of steel pipe piles and the uplift deformation of the pit bottom were analyzed.[Findings]The cofferdam foundation pit has a special problem of single-bottom and double-bottom water basin effect.In the whole process of cofferdam construction,the horizontal deformation law of steel pipe piles is similar in all working conditions and reaches the maximum horizontal deformation of 20.72 mm at 14 m below the pile top at the completion stage of the main pier construction.The horizontal deformation of steel pipe piles reaches its peak when the width of the thin soil interlayer,the length of the steel pipe piles,and the distance between the thin soil interlayer and the bottom of the steel pipe piles are 25 m,35 m,and 0 m,respectively.The thin soil interlayer has a certain water blocking effect,and appropriately extending the length of the steel pipe piles to the thin soil interlayer can increase the deformation stability of the pit bottom.[Conclusions]Once the double-bottom water basin effect formed by the thin soil interlayer in the sand layer and the cofferdam sealing bottom is utilized properly,the stability of the cofferdam base can be improved effectively.The research results of this paper can provide a reference for similar engineering problems.关键词
水盆效应/影响机制/钢管桩围堰/薄土夹层/流固耦合/时空演化特性Key words
water basin effect/influencing mechanism/steel pipe pile cofferdam/thin soil interlayer/hydrologic-mechanical coupling/temporal and spatial evolution characteristics分类
土木建筑引用本文复制引用
李国锋,康佐,周晓燕,张鑫,严周欣荣,李宁..围堰基坑的水盆效应及其影响机制[J].长沙理工大学学报（自然科学版）,2025,22(2):61-77,17.基金项目
国家自然科学基金(52179111、52309144),国家资助博士后研究人员计划与国家博后面上基金(GZC20232139、2024M762626) Projects(52179111,52309144)supported by the National Natural Science Foundation of China （52179111、52309144）
Projects(GZC20232139,2024M762626)supported by the Postdoctoral Fellowship Program of CPSF and General Program for Postdoctoral Fellowship （GZC20232139,2024M762626）
