ABSTRACT
This chapter presents the experimental test campaign and the calibration of the finite element model of a historical masonry bridge almost completely built with travertine blocks. The bridge has undergone very complex vicissitudes related mainly to exceptional river floods; it was partially rebuilt twice and other strengthening works were carried out over the time. Vibration tests were carried out to evaluate the modal properties of the bridge. Evaluation of a historical masonry structure is a difficult task because of many uncertainties associated with the knowledge of the structure in its current conditions and also due to modelling techniques complexity as well as to analysis methods. The modal parameters of the bridge, that is, natural frequencies, damping ratios and mode shapes, are experimentally estimated by means of operational modal analysis starting from the accelerations of the deck recorded during ambient vibration meas-urements which are mainly due to traffic, wind and microtremors.
