广州明珠湾大桥主桥总体设计

Overall Design of Main Bridge of Mingzhu Bay Bridge in Guangzhou

广州明珠湾大桥主桥为(96+164+436+164+96+60)m中承式钢桁拱桥,采用双层桥面布置。大桥主跨采用结构自平衡体系,无外部推力;主梁采用N形三主桁钢桁梁结构;拱肋、钢桁梁均采用箱形截面,腹杆部分采用工字形截面、部分采用箱形截面,弦杆、腹杆与主桁架之间采用栓焊结合连接方式;桥面板采用正交异性钢桥面板,桥面铺装采用浇筑式沥青混凝土;主跨吊杆采用1670 MPa的镀锌平行钢丝索;主墩深水基础采用钻孔灌注桩基础。采用12000 t级双曲面球型减隔震支座,解决了全桥强震作用下的纵、横向减隔震问题。在主墩与边墩分别设置B型转筒式与C型护舷防撞装置,可有效预防3000 t级船舶失控对大桥的撞击。为提高架梁效率、适应通航水域条件,大桥架设采用拱梁同步施工方案。采用MIDAS Civil软件建立全桥空间有限元模型,对该桥静力、动力、稳定、抗风、抗震性能进行分析,结果表明:主桥最大悬臂施工与运营阶段,抖振响应均能满足规范要求,大桥结构受力性能良好、安全可靠。

The main bridge of Mingzhu Bay Bridge in Guangzhou is a half-through steel truss arch bridge with six spans of 96,164,436,164,96 and 60 m,accommodating two levels of decks.mainspan of the bridge is a self-balancing system free of external thrust.The main girder consists of three N-shaped trusses.The arch ribs and steel truss girder are all of box cross-section.The web members are primanily I cross-section web members,with a small number of box cross-section web members in local parts.The chords,web members and main truss are connected by combination of bolting and welding.The orthotropic steel deck is paved with gussasphalt concrete.The hangers are made of 1670 MPa galvanized parallel steel wires.The main piers that stand in deep water area are supported on bored pile foundations.The 12000 t-grade spherical bearings with double curved surfaces are used to address the longitudinal and lateral vibrations of the overall bridge under intense seismic actions.The main and side piers are protected from ship collision by the B-shaped rotating drums and C-shaped fenders,which can effectively prevent the piers from collision events of 3000 t ships.To improve the girder erection efficiency and suit the conditions of navigation area,the construction of the arch ribs and the girder was carried out in parallel.The spatial finite element model of the overall bridge was established by MIDAS Civil to analyze the static and dynamic stability,wind resistance and seismic performance of the bridge.The results show that the buffeting response of the main bridge in both the largest-cantilever and operation states can meet the code requirements,the load bearing performance of the bridge is sound and the structure is safe.