Studying the dome of Pisa Cathedral via a modern reinterpretation of Durand-Claye's method

The dome of the Pisa cathedral is a masonry structure of great interest for many aspects related to history, architecture, building techniques as well as geometry and mechanical behaviour. This Romanesque dome presents a peculiar shape, with an oval base and a pointed profile. Scaffolding has recently been erected in order to perform the restoration operations in preparation for the 900th anniversary of the cathedral’s dedication. Thanks to the cooperation of the Opera della Primaziale Pisana, this has provided a unique opportunity to carry out a research project aimed at an overall analysis of the dome, including its shape, building details, material properties and the state of preservation of the intrados and extrados surfaces. The present contribution, part of the aforementioned research project, focuses on a modern translation of Durand-Claye’s method in order to perform a preliminary study of the mechanical response of the dome. The results obtained can provide an estimate of the geometrical safety factor for the dome under vertical loads. In terms of conventional limit thickness the results suggest that the Pisa dome is a safe structure.