Dynamic identification of a railway bridge with prestressed concrete box beams

Dynamic monitoring of infrastructures has become increasingly important in the last decade because of their ageing and deterioration, and the need to evaluate their safety levels and rationally plan maintenance activities. The current paper presents the dynamic identification of a railway bridge with prestressed concrete box girders, based on acceleration recordings performed in operating conditions. Through the analysis of experimental data, natural frequencies, damping factors and mode shapes of the main modes were estimated. A finite element model was then defined in order to simulate the experimental data. The paper presents a comparison between the predictions of this model and experimental data and discusses their accuracy.