The paper is divided in three parts. In the first part the history of the domes and their realisation are AX,Db%`l,
shortly presented: the Pantheon, Hagia Sophia, St. Mary of the Flower in Florence, St. Peter in f.P( {PN
Rome. w%_BX3GTO
In the second part the behaviour of Hagia Sophia is analysed through its history, the observation of |Gf{ }
the present damage and mathematical models. The study shows how the dome collapsed several bp $jD
times in its history. {PVu3 W
The third part shows the collapse of two vaults of the Basilica of St. Francis of Assisi hit by a strong 7.Mh$?;i9
earthquake on 26 September, 1997. 9bNI aC*M
The mathematical model and photographic records explain the mechanism of collapse. Finally the R]Yhuo9,&n
reinforcements have been achieved using composite materials with aramidic fibers to strengthen the |"-,C} O
deformed existing vaults.
