Dynamic Response Influences of Combination Loads of Wind, Wave, and Current on Sea-Crossing Bridges

To investigate the wind, wave, and current loads and their combination influences on sea-crossing bridge, the joint committee on structural safety (JCSS) combination model was used to combine the wind, wave, and current loads considering the correlations among wind, wave, and current. The Gumbel joint probability model was adopted for the correlation of wind and wave, the combination of current and wind field was achieved by wind current. Taking a sea-crossing bridge as an engineering background, the influences and mechanism of dynamic responses on main beam were analyzed in different combinations, and the influences of secondary load period and different wave fields within load combination on calculation results were discussed. The results show that wind, wave, and current load have great influence on displacement responses of main beam, the displacement responses of the middle span of the JCSS combination with wind as the main load are larger 20%−30% than wave and current as the main load; the random wave and transverse basic mode of bridge are contribute to the lateral responses of the middle span significantly; the displacement responses at different positions of the main beam are affected by the same environmental loads differently, the responses of the middle span are mainly affected by the wind load, the main beam responses at the joint of the tower and beam are mainly affected by the wave load; the wave field simulated by regular wave will underestimate displacement responses of the middle span.