Vault

A vault is designed according to the same principles of geometry and constructive systems as the arch. It is intended both for the total or partial covering of buildings and for the structure of other types of construction elements, thus serving as a floor structure. It consists of a structure suitable for covering spaces by means of architectural elements that work under compression and whose stresses are similar to those of an arch. Like the arch, the vault is composed of different construction elements and materials, supported by one another and resting on supporting walls. All its parts sustain each other, since all its arches converge toward the centre—the point where thrust is generated—although, from a structural point of view, the vault is more complex due to the imposition, accumulation, and overload of internal forces, particularly horizontal thrusts. The construction processes of vaults are varied and may or may not involve the use of formwork (centering). The different solutions found for these constructive processes are related to their mechanical efficiency in resisting internal and external loads, always depending on the containment of the pressure curve within the vaulted section and its vertical supports (i.e., the supporting walls). Depending on the surface, the respective elements, and the spaces involved, the vault receives different designations. "DELLE MANIERE DE'VOLTI Sei sono le maniere de'volti cioè à crociera, à fascia, à remenato (che cosi chiamano i volti, che sono di portione di cerchio, e no arrivano al semicircolo) ritondi, à lunette, & à conca: i quali hanno di frezza il terzo della larghezza della stanza. Le due ultime maniere sono state ritrovate da'Moderni: delle quattro prime si servirono ancho gli Antichi. I volti tondi si fanno nelle stanze in quadro: & il modo di farli è tale. Si lasciano ne gli angoli della stanza alcuni smussi, che togliono suso il mezo tondo del volto: il quale nel mezo viene ad essere à remenato; e quanto più s'approssima à gli angoli; tanto più diventa ritondo. Di questa forte n'è uno in Roma nelle Terme di Tito, e quando io lo vidi era in parte ruinato. Ho posto qui di sotto le figure di tutte queste maniere applicate alle forme delle stanze."[L. 1º, Cap. XXIV, 54]