Dynamic identification and health monitoring of two concrete arc bridges

To contain the inconveniences due to a seismic event it is necessary to study in depth the causes of damages of infrastructures and in particular of bridges. In the context of the project sponsored by the Regional road managing authority (Veneto Strade), two concrete arch formed bridges were subject to some experimental and analytical investigation into their dynamic characteristics. The bridges were characterized by a lower arc with or without vertical standings and a set of longitudinal girders bearing a thin slab. Due to their similarities, at first, the bridges were subject to the same system of investigation (sensors and data gathering) thus performing an ambient modal test. Multiple non-simultaneously recorded measurement setups were prepared. Applying this identification method, the first principal natural frequencies could be identified. Consequently finite element models were updated and adjusted in order to extrapolate natural frequencies and mode shapes.