The paper is divided in three parts. In the first part the history of the domes and their realisation are GW P d v
shortly presented: the Pantheon, Hagia Sophia, St. Mary of the Flower in Florence, St. Peter in BNu cc']
Rome. %N ARyz
In the second part the behaviour of Hagia Sophia is analysed through its history, the observation of Qt+:4{He
the present damage and mathematical models. The study shows how the dome collapsed several b ,^*mx=
times in its history. S h4w qf
The third part shows the collapse of two vaults of the Basilica of St. Francis of Assisi hit by a strong <7sIm^N
earthquake on 26 September, 1997. -kj< 1~YW
The mathematical model and photographic records explain the mechanism of collapse. Finally the b~0N^p[&%
reinforcements have been achieved using composite materials with aramidic fibers to strengthen the .tXt cf/
deformed existing vaults.
