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This paper describes results from a study on the dynamic behaviour of the Confederation Bridge due to seismic loads. For the purpose of the seismic analysis of the bridge, a finite element model was developed using three-dimensional (3D) beam elements. The model was calibrated using measured data of the bridge vibrations during a dynamic load test. Dynamic analyses were conducted by subjecting the model to selected seismic ground motions representative of the expected motions at the bridge location. The bending moments and displacements obtained from the analyses were used for the seismic evaluation of the bridge. It was found that the seismic effects considered in the design are appropriate for the required safety during the service life of the bridge. Cet article décrit les résultats d’une étude sur le comportement dynamique du Pont de la Confédération lors de charges sismiques. Un modèle par éléments finis utilisant des poutres tridimensionnelles a été développé aux fins de l’analyse sismique du pont. Le modèle a été étalonné en utilisant les données mesurées des vibrations du pont durant un test de charge sismique. Des analyses dynamiques ont été réalisées en soumettant le modèle à des mouvements sismiques du sol choisis représentant les mouvements prévus à l’emplacement du pont. Les moments de flexion et les déplacements obtenus des analyses ont été utilisés pout l’évaluation sismique du pont. Il a été conclu que les effets sismiques utilisés dans la conception sont appropriés pour le niveau de sécurité requis durant la vie du pont. [ABSTRACT FROM AUTHOR]

This paper describes results from a study of the dynamic performance of the Confederation Bridge during traffic load tests and a storm with high winds that occurred at the bridge site on 7 November 2001. The traffic load tests were conducted over a three-span segment of the bridge and consisted of single and double truck configurations at different speeds. The winds during the storm of 7 November 2001 were the strongest that have ever been measured at the bridge site since the opening of the bridge. The vibrations of the bridge during both the load tests and the storm were recorded by a network of 76 accelerometers. By processing the recorded vibrations, vertical deflections and dynamic amplification factors due to the traffic load tests and vertical and lateral deflections due to the wind during the storm were computed. The computed values were compared with those used in the design. It was found that both the deflections and the dynamic amplification factors were much smaller than the design values. [ABSTRACT FROM AUTHOR]