SEISMIC BEHAVIOUR OF MASONRY DOMES AND VAULTS HAGIA SOPHIA IN ISTANBUL AND ST. FRANCIS IN ASSISI

The paper is divided in three parts. In the first part the history of the domes and their realisation are shortly presented: the Pantheon, Hagia Sophia, St. Mary of the Flower in Florence, St. Peter in Rome. In the second part the behaviour of Hagia Sophia is analysed through its history, the observation of the present damage and mathematical models. The study shows how the dome collapsed several times in its history. The third part shows the collapse of two vaults of the Basilica of St. Francis of Assisi hit by a strong earthquake on 26 September, 1997. The mathematical model and photographic records explain the mechanism of collapse. Finally the reinforcements have been achieved using composite materials with aramidic fibers to strengthen the deformed existing vaults.