Extreme Response of a Sea-Crossing Bridge Tower under Correlated Wind and Waves

This numerical study focuses on the extreme response of a sea-crossing bridge tower under correlated wind and waves in order to predict structural response with sufficient accuracy. The wind and wave data were obtained by field measurements, and different copula models were compared by Akaike information criterion (AIC), under which the optimal model was selected to simulate the correlation of wind and wave parameters. The fluctuating wind considering multipoint correlation was then simulated by a spectral representation model (SRM), and the random wave considering pile group was generated by a linear superposition method. After verifying the reliability of the numerical method by comparison with an experiment case, dynamic responses of the bridge tower in the freestanding status under directional extreme wind and wave loads are carefully discussed. Furthermore, the response surface method (RSM) is proposed to improve computational efficiency and systematically evaluate the dynamic behavior of the bridge tower. The results show that the response of the bridge tower is highly sensitive to the load direction of wind and waves. The response contours indicate that the tower top displacement is mainly dominated by wind loads, but the base shear is dominated by wave loads.