Preliminary results from a field application of dynamic monitoring on three spans of a railway bridge

Vibration-based Structural Health Monitoring is of the foremost importance for critical civil infrastructures, especially concerning the safety of the train transport network. In fact, even minor structural changes might cause derailment and potentially fatal accidents. This contribution reports some preliminary analyses carried out on 52 accelerometric recordings collected over two consecutive days from three spans of a railroad bridge. The acquisitions include several train passages and the quiet periods between them, when the structure was excited only by ambient vibrations (i.e. random microtremors), thus allowing Ambient Vibration Testing (AVT). Specifically, a newly developed Automated Operational Modal Analysis (AOMA) algorithm was applied. Its results are here compared to state-of-the-art commercial software (ARTeMIS). Some considerations regarding the effects of train passages are also briefly reported, as well as directions for current and future research work in this field.