THE NEOCLASSICAL DOME OF SAN FRANCESCO DI PAOLA IN NAPLES. A STUDY ON FORM AND STABILITY.

The Basilica of San Francesco di Paola, located at the west side of Piazza del Plebiscito, historic center of Naples, was built as a completion of the square in front of the Royal Palace by the will of King Ferdinand IV (1816), designed by the Swiss architect Pietro Bianchi. The "The Bourbon Temple" is mainly characterized by its imposing coverage with hemispherical dome, which protrudes from the complex. It directly refers to the Pantheon for its geometric relations and proportions, its formal and compositive aspects, although it is not completely hemispherical and its interior does not enjoy the spatiality of its model. Further-more in origin the dome ended with a central oculus in which, even today, the structural forc-es converge and balance. Subsequently, a lantern was placed on the oculus, which is a conical element completely in glass that allows the passage of light. The aim of this work is the study of the stability of the dome that, firstly, allows to specify the overall safety of the structure in its current state, especially with regard to statics. Secondly, to assess the degree of seismic safety of the structure, identifying the potential conditions of vulnerability in case of earthquake. The static analysis has been performed, by using the graphical method, according with the principles of the limit analysis applied by Heyman to the masonry structures. The methodological innovation consists in the use of the traditional methods of graphical calculation of masonry structures, interconnected with the new anti-seismic norms in the territory. The operational aspect of the work is contained in the interdis-ciplinarity of scientific fields, with the aim of obtaining a complete knowledge of the monument in its current condition without using an elastic analysis, which would not be suit-able for the study of historical buildings.