G. Chellini, Italy; K. Liu, G. De Roeck, G. Lombaert, B. Peeters, Belgium; L. Nardini, W. Salvatore, Italy
Steel-concrete composite bridges are widely exploited in high-speed lines due to considerable advantages regarding the design, construction time, and costs. The EC research project “DETAILS” (European Research Fund for Coal and Steel) aims at the improvement of design, safety and durability of steel-concrete composite bridges. In order to achieve these objectives, structural analysis is combined with experimental tests in order to obtain more accurate information on actual bridge loading, structural modelling, and fatigue resistance of these types of bridges. As part of the experiments of the project, the Italian Sesia viaduct, a steel concrete composite railway bridge consisting of seven spans, has been tested under both ambient excitation and during the passage of the Italian ETR500Y high-speed train. This paper presents the in situ dynamic measurements and the experimental validation of the numerical model for the prediction of the response of the Sesia viaduct during the passage of a high speed train. The mode shapes of the bridge are extracted from the modal analysis of the ambient vibration data. The dynamic response of the bridge during the passage of high speed trains is predicted and compared with the experimental data. This study provides a better understanding of the structural behavior of a composite railway bridge under the excitation of high speed trains.
