The paper is divided in three parts. In the first part the history of the domes and their realisation are t `\l+L
shortly presented: the Pantheon, Hagia Sophia, St. Mary of the Flower in Florence, St. Peter in o1] 1 I9
Rome. )5;|mV
In the second part the behaviour of Hagia Sophia is analysed through its history, the observation of RhjU ^,%
the present damage and mathematical models. The study shows how the dome collapsed several _J3 \e%ys
times in its history. L`^ v"W()
The third part shows the collapse of two vaults of the Basilica of St. Francis of Assisi hit by a strong 4HXNu, T'
earthquake on 26 September, 1997. dwzk+@]8
The mathematical model and photographic records explain the mechanism of collapse. Finally the W"xRf0\V
reinforcements have been achieved using composite materials with aramidic fibers to strengthen the V+*1?5w
deformed existing vaults.
