Ballast coupling on simply-supported railway bridges with twin decks

Abstract

Short to medium span simply-supported (SS) railway bridges may experience high deck vertical accelerations, compromising the travelling comfort and structural integrity. The accurate prediction of their dynamic response is not an easy task since it depends on complex interaction mechanisms such as vehicle-bridge, soil-structure or track-bridge interaction. The present work contributes to the study of the coupling effect introduced by the continuity of the ballasted track in railway bridges composed by SS spans and adjacent twin decks. With this purpose a 3D finite element (FE) track-bridge interaction model is implemented and updated with experimental measurements performed on an existing railway bridge in a view to evaluate (i) the influence of the track continuity on the bridge modal parameters and on the train-induced vibrations; (ii) the adequacy of the implemented numerical model; and (iii) the importance of this phenomenon for an accurate prediction of the vertical acceleration under operating conditions.