Anatomy of Medieval Masonry of San Niccolò’ Tower-Gate in Florence (Italy), by Mean of NDT and LDT Investigations

The San Niccolò’ Tower-Gate in Florence, designed by Andrea dell’Orcagna, was built in 1328 as part of the third ring of the city walls of Florence. In the frame of a conservation project promoted by the Municipality of Florence, Belle Arti Office, the Department of Earth Sciences of the University of Florence conducted a series of studies, using NDT and LDT (No Destructive Test, Low Destructive Test) techniques, to characterize the tower’s masonry. The knowledge path followed the Italian Guide Line emitted by the Ministry of Culture for the conservation of historical buildings and the principles established by the International Restoration Charts. This knowledge path had already been tested and followed for the study of several other historical Florentine cultural heritage buildings. The first step regards the geometric survey and the 3D H-BIM restitution. Particular attention had been paid to the geological and foundation setting as an integral part of the building and to the local seismicity, too. The definition of the masonry structure and assemblages had been performed by using seismic, georadar, sonic, and sclerometric investigations. The Tower-Gate’s masonry results showed it to be very well constructed, being in the standard of the historical Florentine buildings of that time. After eight centuries since its construction, the San Niccolò’ Tower-Gate displays a good conservation condition according to the principles of Integrity and Authenticity.