Author(s)

C. Gentile & N. Gallino

Abstract

This paper summarizes the dynamics-based assessment of a historic reinforced concrete arch bridge. The bridge, known as Victory bridge and originally constructed in 1923, spans 75 m over a deep valley in the Province of Lecco, Italy. The outlined investigation included ambient vibration testing, output-only modal identification, finite element modelling and updating of the uncertain structural parameters of the model. Keywords: ambient vibration testing, finite element model updating, output-only modal identification, arch bridge. 1 Introduction A great number of reinforced concrete (RC) arch bridges were erected in Italy in the first half of the 20th century, as the concrete arch was the most common solution adopted for bridges spanning over 40 m or more. Of course, these bridges were designed for live loads quite different from automobile traffic they carry today and often require a structural condition assessment. A good example is the Victory bridge [1], completed in 1923 and located about 75 km from Milan. Within an advanced maintenance program, the Province of Lecco, owner of the bridge, planned extensive investigations of the bridge, including: a) review of the bridge history, with an emphasis on the structural modifications of 1984. A great amount of documents and design drawings has been found in the archives and both the original and the current geometry of the bridge were reconstructed with fair accuracy; b) visual inspection and topographic survey of the bridge; c) ambient vibration testing; d) live load static tests and laboratory tests on few cored samples of the bridge concrete to estimate the strength and the elastic properties;

Keywords

ambient vibration testing, finite element model updating, output-only modal identification, arch bridge.