防渗墙缺陷对围堰渗流及变形场的影响研究

Study on Influence of Defects in Anti-seepage Wall on Seepage and Deformation of Cofferdam

防渗墙缺陷是水利工程施工运维期间不可避免的工程问题,准确、系统地分析防渗墙缺陷对围堰的影响是评价围堰稳定性的重要条件。基于某土石围堰中混凝土防渗墙,建立有限元模型,采用流固耦合计算方法,通过改变有限元模型中防渗墙单元的材料参数模拟防渗墙的不同缺陷,系统地研究了防渗墙缺陷位置对围堰浸润线、流速矢量场及变形场的影响。结果表明,防渗墙底部缺陷对围堰浸润线、流速矢量场和变形场影响不大,随着防渗墙缺陷的上移,防渗墙后围堰浸润线、孔隙水压力值和变形值不断升高;围堰流速在缺陷区域呈“沙漏”状,最大流速先增大后趋于稳定,发生位置由围堰溢出位置移动至缺陷区域。研究结果可为防渗墙设计施工和围堰稳定性分析提供参考。

During construction and operation,it is inevitable to have such engineering problems as cutoff wall defects.It is very important to accurately and systematically analyze the influence of defects in anti-seepage wall on seepage and deformation of cofferdam.The finite element model of an anti-seepage wall cofferdam project was established.By using the fluid-solid coupling analysis method,the material parameters of anti-seepage wall element in the finite element model were changed one by one to simulate different defects of anti-seepage wall.The influence of defect location of anti-seepage wall on saturation line,velocity vector field and deformation field of cofferdam was studied.The results show that the bottom defects of the anti-seepage wall have little influence on the saturation line,velocity vector field and deformation field of the cofferdam.With the upward movement of the anti-seepage wall defects,saturation line,pore water pressure and deformation value of the cofferdam behind the anti-seepage wall increase continuously,and the velocity of the cofferdam increases firstly and then tends to be stable.The research results can provide reference for the design and construction of anti-seepage wall and stability analysis of cofferdam.