The “Voltone” (i.e., the great vault) is a 220-meter long masonry structure located beneath Piazza della Repubblica in Livorno. It is constituted by a segmental vault, through which the “Fosso Reale” canal flows. The vault is set on two lateral walls and strengthened by buttresses placed at intervals of about 5 meters one from the other.

The aim of the study was to carry out a realistic analysis of the structural behaviour of the vault with the finite element code NOSA-ITACA. To this end, it is necessary to know the precise geometry of the construction, the mechanical properties of its constituent materials, the characteristics of the soil and surrounding structures, and to assess the permanent and any accidental loads acting on the structure as well.

A series of non-destructive tests (laser scan, georadar and digital acquisition) was conducted, and a few vertical core samples extracted from the vault and wall, with the aim of accurately measuring the thickness of the masonries and determining the stratigraphy and mechanical properties of their constituent materials.

The results of these tests, conducted by IGEAM srl, were then supplemented by data gathered from historical and archaeological reports. Although the collected material samples are currently still undergoing analyses, the information already at our disposal has allowed us to build a three-dimensional model, which has been used for some preliminary static analyses of the structure.