上承式异型拱桥的设计

Design of Deck Special-Shape Arch Bridge

异型拱具有较好的美学特征,常见于景观桥的选型。现有的异型拱桥多为下承式系杆拱,缺乏上承式异型拱桥的应用案例。首先通过两个算例研究了上承式异型拱桥主拱圈受力优化的两种方法:一是改变拱轴线线型;二是采用未知荷载系数法改变拱上荷载分布。文中算例表明,两种优化方法均可用于上承式异型拱桥主拱圈弯矩的优化,且优化效果显著。最后,用某上承式异型拱桥的设计实例介绍了异型拱桥的总体设计思路,为该类桥梁的设计提供了参考。

pecial-shape arches have excellent aesthetic characteristics,and widely apply to the selection oflandscape bridges. The existing special-shape arch bridges are mostly used in tied-arch bridges,but there isno application case of the deck arch bridge.In this paper,two methods for optimizing the force of main arch ringof the deck special-shape arch bridge are presented through two examples:one is to change the arch axisshape,the other is to change the load distribution on the arch by using the unknown load coefficient method.The examples show that both optimization methods can be applied to optimize the bending moment of the mainarch ring of the deck special-shape arch bridge,and the optimization effect is remarkable.Finally,this paperintroduces the general design idea of the special-shape arch bridge with a real engineering example of a deckarch bridge,which provides a reference for the design of similar bridge.