Influence of the Double Composite Action Solution in the Behavior of a High-Speed Railway Viaduct

Abstract This paper addresses the dynamic behavior of the La Scarpe viaduct, which consists of a continuous nine-span steel–concrete composite bridge belonging to the French HSR line TGV Nord. The main objective of the paper is to compare the responses of the existing viaduct with an alternative solution using a double composite action deck with a lower concrete slab in support regions. This slab stabilizes the compression flange, resulting in a reduction in the weight of steel and, consequently, a cost reduction of the global price of the structure. The model of the existing solution is validated with numerical and experimental results presented in the literature. The dynamic analyses performed in this work have been carried out with moving load models using the modal superposition method. The results permit us to draw conclusions between the advantages and disadvantages of the two studied solutions, mostly in terms of the global response of the bridge and in terms of the requirements proposed by the European standards in terms of traffic safety.