Monitoring systems on historic buildings: The Brunelleschi Dome

A digitally controlled monitoring system has been installed to observe and control the propagation of cracks in the Dome of Santa Maria del Fiore cathedral in Firenze, Italy. This system has been in operation since 1988. This paper describes the Brunelleschi Dome structure, the development of cracks, and the monitoring system. The monitoring of data is evaluated based with an understanding of the structural behavior of the Dome. Presently the behavior is very different than it was earlier because of the presence of the cracks themselves. The correlation between crack width variation and environmental loads is analyzed. A numerical procedure was developed to estimate the trend of the increasing crack mean width. The results are compared to those obtained by the analysis of other monitoring systems previously installed in the Dome and historical data. Some considerations and suggestions about the use of monitoring systems in the field of the structural preservation of historic buildings are also discussed.