钢管混凝土拱桥四管与六管拱肋之比较

为了能更好的选取大跨度钢管混凝土拱桥拱肋的钢管数目及布置形式，根据国内已建成的钢管混凝土拱桥，构造了两座400m跨度，宽27．5m，拱轴线形一致的钢管混凝土桁式拱桥（一座为四管拱肋，另一座为六管拱肋），运用ANSYS软件建立了两个全桥模型，分析了它们的静力和动力特性，并讨论了拱肋刚度、含钢率和力学性能三者之间的关系．通过比较发现，六管优于四管．在满足结构要求和强度要求的前提下，对拱肋的刚度选取主要从静力方面考虑，用钢量相当时，采用含钢率大的拱肋形式．

Comparison of Arch Rib between Four-Tube CFST Arch Bridge and Six-Tube CFST Arch Bridge

To choose the steel tube number and the disposition form of long span Concrete-Filled steel Tube(CFST) arch bridges, two CFST arch bridges with a span of 400 m, a width of 27.5 m(one was four-tube arch rib and the other was six-tube arch rib), and the same form of arch axes, were designed according to the arch ribs of CFST arch bridges already existing in China. By using ANSYS, two full bridge models were built to analyze the static and dynamic characteristics and to discuss the relationship between the rigidity, the ratio of the steel of the arch rib and their characteristics. After comparing these two models, it was found that six-tube was better than four-tube. On the premise of satisfying the requests of structure and intensity, the rigidity of arch rib was chosen according to the static performance. The big ratio of steel was better when the steel usages were close to the arch rib.