大跨径箱梁桥拼接缝受力性能研究

STUDY ON THE MECHANICAL BEHAVIOR OF SPLIT-JOINT OF LONG-SPAN BOX GIRDER BRIDGES

为研究大跨径箱梁桥拓宽拼接缝的局部受力性能,考虑拼接缝材料、连接构造、接缝宽度3个因素,采用ABAQUS有限元软件,建立拼接缝模型,施加新旧桥之间基础沉降差、混凝土收缩徐变差等作用,对比分析拼接缝的变形、最大应力。结果表明拼接缝采用高延性水泥基复合材料(ECC)比超高性能混凝土(UHPC)更能满足大跨径桥梁拼接处受力和变形的要求;相比于普通钢筋,配置波形钢板能发挥拉伸效应,接缝与两侧箱梁主体整体受力更协调;接缝宽度增大,能降低两侧箱梁的应力,但不能充分发挥波形板的整体抗拉作用。通过分析提出拼接缝优化方案,为大跨径箱梁桥拓宽设计提供参考。

Considering the material,connection structure,and width of joints a numerical model is established by ABAQUS to study the local mechanical performance of the joints connecting two large-span box girder bridges.The foundation settlement difference,and the creep difference and the shrinkage in concrete between two bridges are ap-plied on the joints,after which the deformation and maximum stress of the joints are compared.The results show that Engineered Cementitious Composites(ECC)for joints can meet the requirements of stress and deformation of joints of large-span bridges than Ultra-High Performance Concrete(UHPC).Compared with ordinary steel bars,the over-all deformation including joint and the box girders are more coordinated by using corrugated steel plates due to stretching effect.As the width of the joint increasing,the stress of the box girders reduced,however,the tensile ca-pacity of the corrugated plate cannot be fully utilized.Finally,through the analysis,the optimization scheme of the splicing joint is proposed,providing the reference for the widening design of the long-span box girder bridge.