装配式空心板桥铰缝失效机理分析

Analysis on Failure Mechanism of Hinge Joints in Fabricated Hollow Slab Bridges

摘要:

装配式空心板桥梁应用广泛，铰缝的损坏是装配式空心板桥梁的一个常见病害，且对于铰缝失效机理存在争议，多数学者认为铰缝设计存在缺陷，铰缝的损伤是被横向拉应力“拉坏”的。对于老桥的调研，发现铰缝病害出现的比例很高，而对新某桥的调研发现均未出现铰缝问题，若铰缝是“被拉坏的”，那么铰缝问题不能仅存在于老桥中，所以铰缝失效机理还有其他重要原因。利用ABAQUS建立详细的有限元模型，充分考虑了铰缝与空心板之间的接触、铰缝与空心板的连接钢筋，得出铰缝结构受力合理，其中连接钢筋的地位非常重要，若连接钢筋发生锈蚀，铰缝的受力便出现缺陷，所以得出结论：铰缝病害是连接钢筋的锈蚀而引起的。

Abstract:

Fabricated hollow slab bridges are widely used. The damage of hinge joints is a common disease of fabricated hollow slab bridges, and there is controversy over the failure mechanism of hinge joints. Most scholars believe that the design of hinge joints is defective and the hinge joints are damaged by the crosswise tensile stress. For the investigation of the old bridges, it is found that the proportion of hinge joint failure is very high, but there is no problem of hinge joints in the investigation of new bridges. If the hinge joints are damaged, not only the problems of hinge joint exist in the old bridges, but also the failure mechanism of hinge joints has the other important causes. The detailed finite element model is established by using ABAQUS fully to consider the contact between the hinge joint and the hollow slab, and the connecting steel bar between the hinge joint and the hollow slab. It is concluded that the structural stress of the hinge joint is reasonable, in which the position of the connecting steel bar is very important. If the connecting steel bar is rusted, the stress of the hinge joint will be defective. Therefore, it is concluded that the disease of the hinge joint is caused by the corrosion of the connecting steel bar.