Aerostatic and Aerodynamic Stability of Super Long-Span Suspension Bridges with Main Span Exceeding 2000 Meters

To evaluate the wind stability of super long-span suspension bridges with main spans exceeding 2[Formula: see text]000[Formula: see text]m, the south navigation channel of Zhangjinggao Yangtze River Bridge with main span of 2[Formula: see text]300[Formula: see text]m was taken as example, by employing a 3D nonlinear aerostatic and aerodynamic stability analysis procedure for long-span bridges, the dynamic characteristics, aerostatic and aerodynamic stability of the example in completion were first investigated, and its dynamic behavior and wind stability were discussed. Then, the evolutions of structural dynamic properties, aerostatic and aerodynamic stability during the entire construction period were investigated under two deck erection sequences: Sequence A (erecting from midspan toward the towers) and Sequence B (erecting from the towers toward midspan). The resulting evolution laws were presented, and the more favorable deck erection sequence was recommended. The results show that, as compared to the traditional suspension bridges, a super long-span suspension bridge with a main span exceeding 2[Formula: see text]000[Formula: see text]m has lower natural frequencies, aerostatic and especially aerodynamic stability limits. In comparison of the aerostatic stability, the aerodynamic stability is much worse and is reduced significantly by the aerostatic effect. For the bridge during deck erection, the natural frequencies, the aerostatic and aerodynamic stability limits are much less than those of the bridge in completion, and exhibit obviously different evolution laws under different deck erection sequences. Integrating dynamic characteristics, aerostatic and aerodynamic stability, Sequence B is superior to Sequence A, and it is recommended for the deck erection of super long-span suspension bridges.