Safety assessment of a short span railway bridge for high-speed traffic using simulation techniques

The dynamic behaviour of railway bridges in high-speed lines has been the subject of several studies in recent years. Nevertheless, most of the work was developed assuming a deterministic perspective. In this paper a probabilistic approach is used to analyse the sensitivity of the dynamic response of a small span bridge due to the variability of the main structural parameters. A filler beam railway bridge was selected as case study and random variables were identified. A variable screening procedure was performed in order to determine which variables had a higher influence on the dynamic response of the bridge. Simulation techniques were applied to analyse the variability of the dynamic response of the bridge, as these methods allow an accurate consideration of the randomness of the main structural parameters. Based on the simulation results, a traffic safety assessment of the bridge was performed. As conclusion, the safety assessment results are discussed, with special focus on the comparison between the results obtained when adopting the European standards approach and when considering a probabilistic approach.

► Dynamic response variability analysis of a short span filler beam railway bridge.
► Simulation techniques applied to reflect randomness of the structural parameters.
► Resonance effects drastically increase the required number of simulations.
► Traffic safety assessment showed that the bridge speed limit should be 295 km/h.
► Eurocode safety coefficient of 2 for ballasted tracks seems very conservative.