This work is part of a current project developed in collaboration with the Local Highway Authority of the Friuli Venezia Giulia, a region located in the North East of Italy. Aim of the project is to define a periodic structural-condition monitoring of bridge structures based on dynamic measurements to ensure that they provide a continued and safe service. The main objective of this paper is to present the results of structural identification based on dynamic data on a two-span post-tensioned reinforced concrete bridge recently built in an area of high seismicity. The span length is 37.5 m and the deck is simply supported by two multi-directional elastomeric seismic bearings on each abutment and on the central pier. Harmonic forced vibration tests with vertical, transversal and longitudinal direction of the excitation were carried out to determine the dynamic parameters of the lower vibration modes of the bridge. An identification procedure based on modal analysis and finite element model updating is presented for the characterization of the bridge and, particularly, for the identification of the stiffness of the bearing devices supporting the deck superstructure.
