大跨径上承式梁拱组合刚构桥设计原理和方法

Design theory and method for long-span arch-stiffened girder rigid-frame bridge

为丰富山区大跨径桥梁选型,寻求更为经济合理、受力高效的桥梁结构体系,提出一种将常规连续刚构和上承式拱桥组合的新桥型——上承式梁拱组合刚构(arch-stiffened girder rigid-frame,ASGRF)桥。文中论述了该桥型的总体布置形式、受力机理、结构设计原理,以及推荐采用的建造方法;通过有限元拓扑优化找形和设计参数正交试验相结合确定主要结构参数建议取值范围,并提出合理成桥状态设计控制方法。在此基础上,开展245m主跨条件下空腹段不设拱上立柱的空腹式ASGRF桥工程应用实践,以及330m主跨条件下空腹段设倾斜拱上立柱和斜拉杆的桁式ASGRF桥试设计。研究表明:ASGRF桥适用于山岭重丘区的高墩、大跨桥梁建设需求,其工程造价指标和结构性能优于同条件下的连续刚构桥,为主孔跨径在200~350m的拟建桥梁增添一种可选经济适用桥型。

To enrich the selection of long-span bridges in mountainous areas and to seek a more economical and reasonable bridge structure system with high efficiency,this paper proposed a novel arch-stiffened girder rigid-frame(ASGRF)bridge that combines a conventional continuous rigid-frame bridge and a deck arch bridge.The general arrangement,load mechanism,structural design principles,and the recommended construction methods for this type of bridge were discussed.The recommended range of values for the major structural parameters and rational design control method for the bridge's finished state were also developed by using the finite element topology optimization and orthogonal testing of design parameters.Furthermore,the engineering application was conducted on an open-web ASGRF bridge with no columns in the open-web sections under the 245 m main-span circumstances,and then designed a 330 m-span truss-girder-arch combined ASCRF bridge with open-web sections.The research results show that the engineering cost indicators and structural performance of ASGRF bridges are better than the continuous rigid-frame bridge under the same condition.The ASGRF bridge is suitable structural type for the high-pier and long-span bridges in the hilly area,adding an optional choice for the main span between 200~350 m.