Description
Vibration-based monitoring is receiving increasing attention in Civil Engineering but practical applications on heritage structures are still not frequent. Since October 2018, a dynamic monitoring system is active in the Milan Cathedral with the main objective of continuously extracting features which are representative of the current state of structural health.
The paper is aimed at presenting selected results from the monitoring of the Milan Cathedral by applying the statistical pattern recognition framework to the dynamic responses continuously collected during about 5 years.
After a concise historic background on the monument and a description of the implemented monitoring system, the paper focuses on the dynamic characteristics of the building. The evolution in time of the automatically identified modal parameters is presented and discussed, with special attention being given to the influence of environmental parameters on the variations observed in the dynamic characteristics of the building. Once the correlation between environmental changes and natural frequencies has been highlighted, various techniques are applied to remove the variance of natural frequencies that is associated to environmental factors and statistical health indicators are evaluated.
Finally, as the responses to a couple of significant seismic events were recorded in December 2020 and December 2021, comments are given on the seismic behavior of the cathedral.
