Operational Modal Analysis of a RC Arch Bridge

In recent decades, the development of methods to improve structural safety and to accurately and reliably assess the condition of structures has become very important. This paper presents the operational modal analysis (OMA) and finite element (FE) model tuning for an arch bridge in the province of Bergamo, Italy. The study was carried out to compare the modal parameters after the replacement of the hangers due to their corrosion condition, and to obtain a reliable finite element model for further analyses. The bridge consists of a reinforced concrete deck supported by two reinforced concrete arch ribs in which hangers made of ordinary steel bars are anchored. Piezoelectric and MEMS accelerometers were used to record the vibrations under operating conditions in order to carry out modal identification. Finally, an FE model was developed and updated in accordance with the experimental modal parameters.