Hydrodynamic interaction of floating bridge pontoons and its effect on the bridge dynamic responses

ABSTR A C T As pontoons of floating bridges respond to the dynamic actions of the wind and wave loading, additional forces are imposed on the pontoons due to the hydrodynamic interaction of these floating bodies. The wave forces on a selected pontoon and consequently its motion are affected by the presence and motion of adjacent pontoons through the motion of the fluid between the bodies. Here, we investigate the effect of such interactions on the global bridge dynamic re-sponses. The hydrodynamic interaction effects are modeled using multibody potential theory with added artificial damping. The stochastic dynamic analyses of the bridge in the frequency-domain under combined wind and wave excitation revealed significant differences in the girder section forces when the interaction effects were included. The results imply that the hydrodynamic interaction effects should be considered in the design of such structures. The methodology pre-sented here provides practical means for the analytical assessment of such effects.