tsunami wave loading on a bridge deck with perforations

Tsunamis have damaged bridges to various extents in the 2004 Indian Ocean Tsunami. This paper reports an experimental investigation of the effect of perforations in the girders and parapets on the horizontal tsunami loads. The results reveal that the maximum pressures impinging on the front face of the pier and deck are 4.5 and 3 times the hydrostatic pressure at 80mm nominal wave heights. The percentage of force reduction of the bridge deck with 10% perforated girders and 60% perforated parapets is found to be close to the percentage of perforation area in the deck. However, it is also noted that perforations in the bridge deck can substantially reduce the tsunami forces acting on it throughout the force time history. Thus, less damage to the bridge is anticipated for the bridge deck with perforations in girders and parapets.