Numerical Investigation of the Collision Damage and Residual Strength of a Floating Bridge Girder

Abstract

For bridges across wide and deep waterways, fixed foundation structures are not possible to be built due to technical restrictions. Alternatively, pontoon supported floating bridges which do not require fixed foundations can be installed. As the girders of floating bridges may have a low clearance from the sea level, a critical design consideration is the capability of the girder to resist the collision of passing ships. It is hence important to investigate the collision response of the bridge girder and evaluate girder residual strength after the collision. In this paper, finite element (FE) models of a ship deckhouse and a floating bridge girder are established. The girder response to ship deckhouse collision is investigated through integrated numerical simulations. Parametric studies are conducted to compare the girder response for various girder designs and collision scenarios. The residual strength of the girder after in damaged condition is also investigated. Based on the numerical results, a residual strength index (RSI) is proposed for fast prediction of the girder damage level based on the absorbed energy.