Train-bridge interaction influence on the safety of a short span railway bridge

The behaviour of short span railway bridges is known to be particularly difficult to predict due to the complex coupled train-track-bridge system, as well as for being particularly sensitive to resonant phenomena. The objective of this paper is to evaluate the safety of this type of structure inserted in high speed railway lines, bearing in mind the real variability of the parameters that influence the bridge dynamic response. This requires the definition of variables related to the structure, the train, the track and also the wheel-rail contact. Simulation techniques are used to evaluate the structural safety. The system behaviour is assessed by analysing the results obtained using two distinct methods: the moving loads method and the train-bridge interaction method. This allows assessing the influence of the train-bridge interaction effects on the dynamic response of the bridge, confirming ist importance for the analysis of short span structures, particularly under resonant speeds.