鱼腹式连续箱梁桥设计

Design of fish-belly continuous box girder Bridge

连续梁桥利用支点处产生负弯矩来降低跨中的正弯矩,有效地分散了各截面的受力,由此增大了桥梁跨度。鱼腹式连续箱梁桥的边腹板呈流线形状,增加了界面抗弯、抗扭刚度的同时兼具了外形的美观性。现浇连续箱型梁桥的发展使得桥梁能够适应多种截面形式和道路线形设计,但同时增加了结构的复杂性。因此鱼腹式连续梁桥的计算需要经过精密的计算和调整以保证其安全可靠[1-3]。通过一个鱼腹式连续箱梁桥实例,应用平面及空间有限元模型,对桥梁结构进行计算及调整优化,确保桥梁纵、横向以及桥面板等构件满足受力和抗裂等要求[4],为类似桥型设计提供参考。

The negative bending moment at the fulcrum of continuous beam bridge is used to reduce the positive bending moment in the middle of the span,which effectively disperses the stress of each section,and thus increases the span of the bridge.The side webs of fish bellied continuous box girder bridge are streamline in shape,which not only increases the bending and torsional stiffness of the interface,but also has an aesthetic appearance.The development of cast-in-place continuous box girder bridge enables the bridge to adapt to a variety of cross-sectional forms and alignment designs,but at the same time increases the complexity of the structure.Therefore,the precise calculation and adjustment of the fish-belly continuous girder bridge are needed to ensure its safety and reliability.Through an example of fish-belly continuous box girder bridge,the plane and spatial finite element model is applied to calculate,adjust and optimize the bridge structure,so as to ensure that the longitudinal,transverse and bridge panel meet the requirements of stress and crack resistance,and provide reference for the design of similar bridges.