广珠铁路虎跳门特大桥主拱设计

Design of Main Arch of Hutiaomen Bridge on Guangzhou-Zhuhai Railway

广珠铁路虎跳门特大桥主桥为(120+248+120)m的连续刚构柔性拱组合桥。拱肋采用钢管混凝土结构,由上、中、下弦管组成,弦管内采用C50混凝土,每片拱肋由两管平行管和提篮内倾单管组成,由直腹杆和斜腹杆连接成三肢桁架拱;三角形直腹杆采用矩形钢箱截面,斜腹杆采用圆钢管;全桥拱肋共布置19道横撑;拱座采用实体截面。主桥采用先梁后拱的施工方案。采用MIDAS Civil 2006检算拱肋承载力、结构强度、稳定性等性能,计算结果表明拱肋的静力、动力性能均满足规范要求。

The main bridge of the Hutiaomen Bridge on Guangzhou-Zhuhai Railway is a hybrid bridge of continuous rigid frame structure and flexible arch with span arrangement（120＋248＋120） m.The arch ribs of the bridge employ the concrete-filled steel tube structure formed by the upper,middle and lower chord tubes that are filled in with C50 concrete.Each of the arch ribs is composed of two parallel tubes and an inward inclined tube of basket handle and these tubes are connected into a three-leg（triangular） truss arch by the vertical and inclined web members,of which a vertical member is the rectangular steel box section while an inclined member is the round steel tube section.The arch ribs of the whole bridge have totally 19 cross bracings,the arch seats are the solid sections and the bridge is constructed by way of erecting the girder first and the arch late.The calculation of the bearing capacity,structural strength and stability behavior of the arch ribs is checked by the MIDAS Civil and the results of the checking prove that the static and dynamic behavior of the arch ribs can meet the relevant requirements in the codes.