Dynamic Characterization of a Five Spans Historical Masonry Archbridge

This paper presents the studies carried out on a five spans masonry arch bridge, the Viaduct of Vara, inside the marble caves close to Carrara. The bridge was strengthened in recent time due to the failure of a pier. Two sets of dynamic tests were performed, the first before the strengthening, the second after the strengthening was carried out. A finite element model of the structure was made for preliminary studies. Dynamic tests were necessary to validate numerical results. After describing the way the tests were performed in situ and the instrumentation used for collecting the data, a comparison is made between numerical and experimental modal parameters (before and after the strengthening) of the structure. Signal processing techniques used for modal parameters extraction focus on the use of wavelet transforms, which are a very powerful tool in case the signals are non stationary and with a low signal to noise ratio.