Seismic behaviour of steel-concrete composite bridge decks

The paper focuses on local problems relevant to the seismic response of steel-concrete composite bridge decks. In particular, the local mechanisms involved in the transferring of inertial forces from the slab to substructures are investigated with particular focus on the shear connection and the role of end cross beams. Firstly, open issues relevant to the seismic design and analysis of steel-concrete composite bridge decks are discussed and an overall state-of-art of the problem is depicted. Then, some case studies constituted by single span and two-spans I-shaped twin-girders and box girders steel-concrete composite bridges are selected and adopted to investigate local response of the decks subjected to seismic actions. Linear and non-linear applications are performed adopting different analysis methodologies in order to investigate stress resultants in the shear connection and to analyse the role of the end cross beams on the local transferring mechanisms of inertia forces; results of analyses on the selected case studies are shown and discussed.