SHM Campaign on 138 Spans of Railway Viaducts by Means of OMA and Wireless Sensors Network

Abstract

Condition-based monitoring applied to railway bridges represents a topic of major importance and interest among developed countries, such as Italy. In fact, bridges and viaducts represent key components of the transportation network, and therefore they increasingly draw infrastructure managers' attention. The present work is the result of a project carried out by Politecnico di Milano, consisting of a large experimental campaign conducted on a series of viaducts of the Italian railway network. The ensemble of structures under investigation is composed by 11 viaducts, for a total amount of spans equal to 138. According to a similarity criterion, the latter were subdivided into 8 groups, featured by different properties. Due to its transient nature, the experimental campaign was conducted by means of wireless accelerometers, and it consisted in the extraction of the main modal parameters of each analyzed viaduct span, as well as the characterization of the trains travelling on the line. Through the adoption of an operation modal analysis (OMA) technique, it was then possible to construct a large database of the dynamic features concerning the studied viaducts. This database may be exploited for future studies as an important baseline reference condition, by which potential outlier values may be captured, as a sign of damage occurrence among the monitored structures.

Drive‐by frequencies extraction by means of synchrosqueezed wavelet transform

“…Thus, the modal parameters could be extracted by exploiting the velocimeters placed on the rail deck. Being all the spans featured by the same structural characteristics, their modal parameters resulted to be very similar, as theoretically expected and confirmed by literature [24]. For this reason, the reference to compare the drive-by campaign results with is obtained by statistically aggregating the modal parameters of the spans in terms of a mean value and a related standard deviation.…”

Non-linear vibration signal compensation technique for UAV-deployable sensor packages with edge computing

“…1 Wireless sensing networks have been widely used in the monitoring of civil structures utilizing vibration-based modal analysis algorithms. 2 Of particular interest to this work is the ability to deploy such wireless networks onto currently operational or historic structures while minimizing environmental or cultural concerns. 3 Unmanned aerial vehicles (UAV) are increasingly being used to deploy wireless sensor nodes for SHM applications.…”