Fatigue Assessment of Continuous Composite Bridges Accounting for Slab Casting Sequences

The paper presents a procedure for the fatigue assessment of continuous steel- concrete composite bridges which accounts for concrete slab casting sequences. Cracking, tension stiffening, creep and shrinkage (thermal, endogenous and drying) effects are included in the analysis in order to correctly evaluate the stress state of steel girders. The purpose of the paper is to present a method that, based on the analysis of a number of models developed according to the structure's evolution, leads to a more effective and realistic fatigue assessment than that usually performed in practice. The method proposed is applied to a case study of a continuous, twin-girder, composite bridge deck, showing the influence of three different slab casting modalities on fatigue assessment.