Primato romano delle volte. Il Tempio di Diana a Baia

We have chosen the Temple of Diana because of its unique ovoid shape. Opus caementicium allowed the Romans to build domes and vaults of great amplitude, thanks to an expert use of rubble, mortar, laying techniques and, above all, geometrical parameters, especially as regards the appropriate outline for the span and thickness to ensure stability. The intrados is contained in a hemisphere but it is not one itself. Finally, a set of measurements can be taken across the entire surface to tell us about the geometry and structural behav-iour. Our program extends over three years: in the first, the intrados we are presenting; in the second, the extrados; in the third, the drum, using an ap-proach starting from the dome. Activities to expand our knowledge of the building are based on accurate survey methodologies and data analysis, as well as documentary research. Surface measurements were taken in parallel, using two instrumental techniques: three-dimensional laser scanning and digi-tal photogrammetry. The acquired data allowed us to identify 15 horizontal sections of the vault and 17 vertical radial sections at 10° intervals. The results of the survey were used to investigate the stability of the dome and compare it to other geometric profiles. Map cracking analysis allows us to identify possi-ble damage or collapse mechanisms that explain its present state.