Long-term dynamic monitoring of an iron arch bridge

A multi-channel dynamic monitoring system has been recently installed in a centenary iron arch bridge that crosses the Adda river about 50 km far from Milan: the San Michele bridge. The paper describes the monitoring system and the signal processing tools developed in LabVIEW for automatic processing of the collected data. The implemented routines include the automated identification of the bridge’s modal parameters by using the Frequency Domain Decomposition method. The application of this procedure to the data collected in the first weeks of monitoring turned out to provide a clear and robust tracking of more than 20 natural frequencies.