On the dynamic characterisation of railway bridges through experimental testing

Abstract

This work is devoted to the experimental evaluation of the dynamic response of railway bridges with common typologies in short-to-medium span lengths. An extensive experimental campaign is performed in several railway bridges belonging to the High-Speed (HS) and conventional Spanish railway network. The main objectives are to (i) characterise the structures main features affecting their dynamic behaviour, (ii) determine the soil properties at the structures respective locations; and (iii) analyse the bridge dynamic responses under different operating conditions. All the bridges are composed by simply-supported (S-S) spans except the last one which is a continuous beam bridge. The structures present different steel, concrete and steel–concrete composite typologies. Five bridges have been experimentally investigated. The five bridges are nowadays at full operation. The study includes the identification of the bridges modal parameters and dynamic soil properties at the sites, a discussion on the identified structural damping in all the bridges, the measurement of the vibration levels induced by railway traffic under operational conditions in the first four bridges, and under construction operation machinery in the fifth case, and a final analysis on the differences found in the structural behaviour of the different typologies for similar traffic. This paper summarizes a vast experimental campaign. The data is available and may be useful to other researchers in order to estimate the response in similar cases and to validate numerical models.