Abstract:Vortex-induced vibration of long-span suspension bridges occurs frequently, which seriously affects driving safety and comfort.In order to predict the vortex induced vibration of a long-span suspension bridge in time, a cross sea bridge was taken as an example.Based on the long-term monitoring data of a structural monitoring system, wind velocity, wind direction angle, energy concentration coefficient and acceleration RMS were selected as the characteristic parameters of vortex induced vibration.According to the correlation between the characteristic parameters and the vortex excited vibration, a dynamic monitoring and prediction model of vortex-induced vibration of a cross-sea bridge was constructed, and an independent dynamic monitoring and control system of vortex-induced vibration was established.The results show that: the wind direction is mainly between 300°—330°and 120°—150°, and the energy concentration coefficient (the ratio of power spectral density WP2/WP1) is less than 0.1; the acceleration RMS of the main bridge is more than 5 cm/s2; the prediction recognition rate of the system model is 72%, and the identification accuracy of the vortex induced vibration dynamic monitoring system is 93%.At the same time, the vortex-induced vibration early warning app which is perfectly useful for work has been developed, and it can provide reference for the prediction of vortex-induced vibration of similar bridges.