Optimal sensor placement for the dynamic monitoring of a historical masonry church in central Italy

Italy is a seismic prone country with a great heritage of churches and historic masonry buildings that often suffer damage due to earthquakes. For buildings of high cultural value, the damaged structural systems are usually secured through immediate interventions, with the need of monitoring the evolution of damage in time up to the final restoration. This paper presents some of the results of the research activities carried out on the church of Santa Maria in Via in Camerino, (central Italy), severely damaged by the 2016 Central Italy seismic sequence and secured through various interventions. In particular, a massive external retaining steel structure was built to prevent the collapse of the façade and, in the subsequent years, a static and dynamic monitoring system has been installed with the aim of monitoring the health status of the church and preventing the evolution of the kinematics triggered by the 2016 earthquake. Ambient vibration tests have been performed on the church and its global dynamics has been identified by means of Operational Modal Analysis techniques. Also, a finite element model of the church has been developed, whose parameters have been optimised through the Particle Swarm Optimisation algorithm. Finally, starting from the results of the updated model, the sensor placement was optimised by employing the Effective Independence algorithm, in order to increase the efficiency of the monitoring system in tracking all the preliminarily identified modes.