The paper is divided in three parts. In the first part the history of the domes and their realisation are {q[l4_
shortly presented: the Pantheon, Hagia Sophia, St. Mary of the Flower in Florence, St. Peter in `Eijy3>h
Rome. YM idSfi
In the second part the behaviour of Hagia Sophia is analysed through its history, the observation of 8KQ]3Z9p
the present damage and mathematical models. The study shows how the dome collapsed several me+F0:L
times in its history. us2X:X)
The third part shows the collapse of two vaults of the Basilica of St. Francis of Assisi hit by a strong y3]7^+k
earthquake on 26 September, 1997. UUf-G0/P
The mathematical model and photographic records explain the mechanism of collapse. Finally the 8e`'Ox_5a
reinforcements have been achieved using composite materials with aramidic fibers to strengthen the @o[C
Xrz
deformed existing vaults.
