Effects of air relief openings on the mitigation of solitary wave forces on bridge decks

For inverted T-type bridge decks, the air entrapped in the chambers between adjacent girders could increase the wave forces and lead to the destruction of the bridge decks. This paper studies the effects of the air relief openings (ARO) on the mitigation of the solitary wave-induced forces on the bridge decks. Hydrodynamic experiments are conducted for three inverted T-type decks with four, five, and six girders with different wave properties and deck clearances. The open source computational fluid dynamics toolbox OpenFOAM is adopted to conduct numerical simulations for the effects of the AROs. Since the numerical results correlate well with the measurements, the mechanism of the wave-structure interaction can be revealed by the numerical flow fields. Furthermore, the relationship between the shape and the volume of the ARO and the wave forces on the bridge decks, as well as the contribution of each ARO to the effect of the wave force mitigation, is also obtained from the numerical results of the OpenFOAM. Experimental and numerical results demonstrate that the AROs could effectively reduce the vertical wave forces on the bridge decks. The effects of the AROs increase with the increase of the volume of the ARO, while the shape of the ARO has no effect on the reduction of the wave forces.