Experimental Validation of a Numerical Model for the Dynamic Analysis of a Bowstring Arch Railway Bridge

This paper focuses on the development and experimental validation of a numerical model for the dynamic analysis of São Lourenço railway bridge under traffic loads. The numerical model involves the modelling of the bridge, the train and their dynamic interaction. The preliminary experimental campaign consisted of an ambient vibration test and a dynamic test under traffic loads. The comparison between numerical and experimental natural frequencies and mode shapes revealed important limitations of the initially developed numerical model. The study of the influence of several parameters in the dynamic properties of the structure enabled to identify the inclusion of the track, the mass of the deck, the modulus of elasticity of the concrete and the vertical stiffness of the supports as key parameters for the numerical model updating. The updated numerical model was used for the simulation of the dynamic response of the bridge under traffic loads and a good agreement between numerical and experimental results was obtained.