Experimental investigation of loads of coastal bridge deck under the combined action of extreme winds and waves

In this study, loads on a 1:10-scaled coastal bridge deck model were experimentally investigated under the combined action of extreme winds and waves. The loads and hydrodynamic pressure with respect to different clearances, incident wave heights, wave periods, and wind velocities were analyzed. The experimental results revealed that the wind effects were crucial for the determination of loads on bridges during hurricanes. In small wave-height cases, both the vertical and horizontal forces were enhanced under the combined action. Furthermore, the vertical quasi-static force comprised an additional peak in high-wind-velocity cases. This peak was due to the wind pressure differences on the deck. The falling water and traveling waves had blocking effects on the wind, resulting in positive up wind forces. In large-wave-height cases, the horizontal force was restrained by the wind action. As the wave height increased, the vertical force was also restrained by the wind action until overtopping waves occurred. The results of the pressure at different locations showed that the wind action could enhance the vertical force by increasing the pressure at the rear of the deck. A quadrant analysis showed that extreme winds could significantly increase the combined load at the dangerous state of the bridge deck.