Design of floating bridge girders against accidental ship collision loads

Abstract

<p>The Norwegian Public Roads Administration is running a project “Ferry free coastal route E39” which includes replacing ferry crossings by bridges or tunnels across fjords in Western Norway. A floating bridge concept was proposed in the fjord-crossing project for Bjørnefjorden. As there are regular cruise routes passing by the bridge, it raises the concern for the consequences of accidental ship collision with the bridge girder. During the collision, the interactions between the bridge girder and the ship structure can be significant. Thus, in the design of the proposed bridge it is vital to evaluate the safety of the ship and the bridge. In this paper, detailed finite element models of a cruise ship and a steel box girder are developed. The impact scenarios and structural damages are studied. The results show that the proposed bridge girder design is generally safe to resist normal accidental ship collision loads. Numerical model of the whole bridge is also developed for further study of bridge global response subjected to ship collision load.</p>