Overall Design of Main Bridge of Mingzhu Bay Bridge in Guangzhou

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 1 670 MPa galvanized parallel steel wires. The main piers that stand in deep water area are supported on bored pile foundations. The 12 000 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 3 000 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. © 2021, Journal Press, China Railway Bridge Science Research Institute, Ltd. All right reserved.