Issue 46

A. Maione et alii, Frattura ed Integrità Strutturale, 46 (2018) 240-251; DOI: 10.3221/IGF-ESIS.46.22 247 Therefore, by critically integrating different sources of information, a proper classification of the no-load-bearing vaults was proposed on the basis of their constructive typology and of the overlying horizontal structures. This approach allowed defining a complete typological characterization of the horizontal structures present upon the first floor of the building. In fact, the following typologies can be identified (Fig. 8): – Load-bearing masonry vault; – No-load-bearing masonry vault with overlying load-bearing masonry vault; – No-load-bearing masonry vault with overlying horizontal diaphragm; – No-load-bearing vault composed of timber structure with overlying load-bearing masonry vault; – No-load-bearing vault composed of timber structure with overlying horizontal diaphragm; – No-load-bearing masonry vault with visible extrados; – Horizontal diaphragm. Load-bearing masonry vaults (Fig. 9) have a prevailing configuration as a schifo or mirror vault and maximum height of about 8.8 m; moreover they are dated back to the construction of the building and characterize the rooms of the north and south sides. Their structural behaviour could be easily modelled through validated numerical methods [28-31]. No-load-bearing masonry vaults with overlaying load-bearing masonry vaults have been identified in some rooms of the west side overlooking the north and south courtyards. This solution is likely related to the need of dividing a large room, covered by a masonry vault, in two smaller rooms and is likely contemporary to the last phase of construction. As already shown in Fig. 7, this kind of no-load-bearing vault is built with bricks disposed on a sheet and has thickness of about 20 cm. For some rooms, the documentation related to the interventions dated back to 1985 allowed identifying the presence of tie roads and validating in this way the hypothesis of structural vault overlaying the no-load-bearing one [7]. Figure 8: Typological characterization of the horizontal structures upon the first floor. No-load-bearing masonry vaults with overlying horizontal diaphragms. The historic analysis allowed to refer this typology to two different circumstances: the first one is the substitution of the earlier load-bearing masonry vault with a c.a. diaphragm likely due to structural problems; the other one is related to the project of the architect De Felice of the years between 1952-1957, when new rooms devoted to the exposition were created on the last level of the building and horizontal structures were realized above the vaults of the rooms with double height upon the first level as the "Sala della Culla" (Figs. 2a and 10) and the "Salone delle Feste" (Fig. 2a) [7].