The paper is divided in three parts. In the first part the history of the domes and their realisation are (^|vN ;
shortly presented: the Pantheon, Hagia Sophia, St. Mary of the Flower in Florence, St. Peter in gE&83 i"
Rome. |@D%y &
In the second part the behaviour of Hagia Sophia is analysed through its history, the observation of P1q nU
the present damage and mathematical models. The study shows how the dome collapsed several #9(iu S+BU
times in its history. bhjJH,%_>
The third part shows the collapse of two vaults of the Basilica of St. Francis of Assisi hit by a strong =, U~
earthquake on 26 September, 1997. 0$R}_Ok
The mathematical model and photographic records explain the mechanism of collapse. Finally the ~ Ctq
reinforcements have been achieved using composite materials with aramidic fibers to strengthen the meD?<g4n~"
deformed existing vaults.
