Dynamic Investigation and Short-Monitoring of an Historic Multi-span Masonry Arch Bridge

Abstract

A number of vibration-based Structural Health Monitoring (SHM) algorithms have been developed in the last two decades with the purpose of extracting reliable structural features from recorded dynamic signals. By using a mix of techniques the identified frequencies gain a statistical evidence, as in the procedure used in the validation of the Pontelungo bridge natural frequency set. The Pontelungo Bridge is an historic masonry bridge crossing the Reno River, firstly built in the medieval age and updated several times in its life, resulting so in a very complex geometry and behaviour. A numerical model able to reproduce the experimental frequencies has been obtained through a suitable calibration procedure, based on several iteration steps and FE models of different complexity. The updated model can then be used in checking hypotheses of potential damage scenarios that can emerge as frequency shifts in the bridge monitoring phase. However, in order to have a sound set of frequency values, a long-term monitoring period is needed. This activity has started recently but with consistent results that validate the worked out model.