一种新的公铁两用桥设计与建造可行性分析

Feasibility design and construction of a new highway-railway bridge

为提高公铁两用桥的力学性能,采用悬索桥与拱桥优势互补的理念,提出一种新的公铁两用桥,其主要特征是主缆两端锚固于边拱拱脚或其附近,使拱产生的水平推力与缆产生的水平张力在此处相互平衡,成桥状态下对基础不产生推、拉力,桥面荷载由拱肋与主缆共同承担。以420 m主跨为例,对其进行设计和建造技术的可行性研究,结果表明,新结构兼具悬索结构和拱结构的优点,力学性能优越、造价经济,是公铁两用桥的又一可选桥型,可尽早进行推广应用。

In order to improve the mechanical properties of highway-railway bridges,a new highway-railway bridge combining the complementary advantages of suspension bridges and arch bridges is proposed.The main features of the structure are that the two ends of the cable are anchored at or near the arch foots of the side arch,so that the horizontal thrust produced by the arch structure and the horizontal tension produced by the cable structure are balanced.The foundation is not pushed or pulled when the bridge is completed,the travel loading on the bridge deck is shared by the arch rib and the cable.A feasibility study on design and construction techniques of 420 m-span was conducted.The results show that the new structure has the advantages for both suspension structure and arch structure.As for superior mechanical properties and economical efficiency,it is an optional type of bridge.The highway-railway bridge should be put into engineering practice and develop as soon as possible.