Advanced aerodynamic stability analysis of long-span suspension bridges

As the span length of suspension bridges increases, the diameter of cables and thus the aerodynamic forces acting on them, the static wind action and the spatial non-uniformity of wind speed all increase consequently, which may have non-negligible influence on the aerodynamic stability of long-span suspension bridges. Considering the static wind action and the spatial non-uniformity of wind speed, the model of nonlinear aerodynamic force is presented, and the advanced nonlinear method of aerodynamic stability analysis is then developed. Using this method, aerodynamic stability analysis is conducted on a long-span suspension bridge (Runyang Bridge) with a main span of 1490 m, and the effects of the static wind action, wind speed spatial non-uniformity, and the cable's aerodynamic force on the aerodynamic stability of the bridge are analytically investigated. The results show that the aerodynamic stability is significantly influenced by the static wind action and wind speed spatial non-uniformity, however the cable's aerodynamic force has no influence on it.