ABSTRACT
For large bridges across navigable waterways, one of the key aspects in design is to ensure bridge safety under accidental ship collision loads. Special attention has been paid to quantify the impact demand and structural response of vessel impact on bridge piers and pylons. In addition, residual strength assessment has also been conducted on reinforced concrete columns after ship collisions. Previous studies focused on the collision analysis of bridge substructures while the collision response of bridge superstructures has not been well studied. The ultimate strength of bridge superstructures, especially bridge girders, before and after ship collisions also remains unexplored. This paper presents a numerical procedure for assessing the ultimate strength of steel bridge girders before and after ship deckhouse collisions. The complete procedure consists of three main parts, i.e. estimating ultimate strength before collision, evaluating girder response during collision, and quantifying residual strength after collision. Several critical modelling issues such as explicit and implicit analysis, loading speed and loading directions are addressed. The effect of bridge girder configuration, ship type and relevant limit state design criteria are also discussed.
