双排钢板桩围堰变形特性研究

Deformation characteristics of double-row steel sheet pile cofferdam

针对上海地区河道工程中常见的双排钢板桩围堰结构,通过建立Plaxis有限元模型,研究围堰宽高比、钢板桩插入比、钢板桩型号、拉杆布置等对围堰变形特征的影响。结果表明:增大围堰宽高比在一定范围内能够减小钢板桩的水平位移,并针对不同挡水高度给出宽高比的建议取值;在4 m挡水高度情况下,钢板桩插入比设置为1.1~1.5较为合理;对于一般挡水高度,围堰可以只布置1根拉杆,且拉杆存在最优位置以保证围堰体系的整体变形协调。研究结果可为双排钢板桩围堰的设计提供参考依据。

The double-row steel sheet pile cofferdams are widely used in river engineering in Shanghai.To study the deformation characteristics of this type of cofferdam,we establish the Plaxis finite element model to analyze the effects of the cofferdam width to height ratio,the steel sheet pile insertion ratio,the type of the steel sheet pile and the tie rod arrangement.The results show that increasing the width-height ratio of cofferdam can effectively reduce the horizontal displacement of the steel sheet piles,and the suggested values of the width-height ratio are given for different water retaining heights.It is recommended to set the insertion ratio of steel sheet pile as 1.1~1.5 when the water retaining height is about 4 m.The cofferdam can be arranged with only one tie rod and there exists an optimal position to ensure the overall deformation coordination of the steel sheet piles.This research may serve as reference for the design of double-row steel sheet pile cofferdam.