Results of a 60-Year Monitoring System for Santa Maria del Fiore Dome in Florence

This study aims to present the results of the historical and statistical analysis carried out on the monitoring systems that control one of the most studied domes in the world: Santa Maria del Fiore in Florence, Italy. An accurate analysis of the dome crack widths and of its global displacements (horizontal and vertical), both considering the historical data and more recent data, has allowed detection of the static movements developed in the monument over time as well as in context of their relationship to environmental and seismic phenomena. Thanks to the large amount of measured data (from 1955 to 2010), some previous conclusions on the dome damage trend are updated herein. Moreover, in light of the experimental results, some issues on the dome stability-as the principal hypotheses advanced during centuries about the main cause of Brunelleschi's dome crack pattern-are reconsidered, including the horizontal thrusts due to the dome's self-weight characterized by Viviani in 1695 and Chiarugi in 1985, the differential settlement of pillars detailed by Cecchini in 1698, Ximenes in 1757 and Borga in 1975 and the influence of temperature variations investigated by Nervi in 1934. The final aim of this study is to show the great utility of modern and historical monitoring in setting up a reliable forecasting model of the monument.