No abstract

The Morca footbridge is a historic suspension bridge, originally constructed in 1928. The bridge is characterized by the timber deck supported by two pairs of cables that were recently replaced. After the strengthening, an extensive program of non-destructive global tests was carried out; the field tests included complete geometric survey of the deformed configuration due to dead loads, static load tests and ambient vibration measurements.The experimental investigation was complemented by the development of a 3D finite element model and the correlation between theoretical and experimental results suggested a satisfactory state of preservation of the deck timber elements but also the potential weakness of some nodes. Hence, the dynamic tests were repeated in order to evaluate any changes in the modal parameters and the correlation with structural modifications or damage.

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.

This paper presents the results of a recent research on the dynamic behaviour of an historic bell-tower, built in stonework masonry. The first part of the investigation involved: (a) an accurate survey of the tower geometry and of the crack pattern; (b) ambient vibration testing under wind, micro-tremors and swinging of bells; (c) modal identification; (d) FE modelling and model tuning.Since the amplitude of the excitation seems to affect the modal behaviour of the structure, a permanent dynamic monitoring system was recently installed inside the tower in order to investigate the changes in the modal parameters and the possible correlation with damage.