桩围软体截流坝的工作性态研究

Filed Test and FEM Analysis of Soft Cofferdam

针对城市河流改造中传统围堰施工过程中存在影响通航和污染河道等问题,提出了桩围软体截流坝的设计思路。软体截流坝采用群桩组成外围框架,构建膜袋,膜袋充水后可挡水、防水防渗,具有结构简单、受力明确的特点。构筑现场模型,对结构进行破坏性试验,膜袋内部分级加水,通过不同水位下钢管桩应变和位移的变化来研究软体截流坝的破坏机理和杆件受力特性。利用大型有限元软件ADINA进行有限元分析,求解在外荷载作用下结构的变形和应力,与现场试验结果进行相互验证,以证明本方法的合理性和正确性,为桩围软体坝的设计、施工和推广应用提供了依据。

For the defect of traditional cofferdam in transformation of urban rivers, the soft cofferdam using steel pile and membrane was proposed. The soft cofferdam resisted the water pressure by the frame composed of the piles, and keeping waterproof and impervious by using the membranes. A site model was built to achieve the failure mechanism and mechanical characteristic of the soft cofferdam by destructive testing. In addition, based on the large-scale universal software ADINA, the deformation and stress of the structure under the external load were analyzed and compared with that of the field test to verify the validity of the method. Moreover, the basis for fur- ther generalization of the soft cofferdam was provided by the comparison and analysis of the field test and FEM method.