A Novel Numerical Tool for Seismic Vulnerability Analysis of Ruins in Archaeological Sites

Ancient masonry constructions in archaeological sites are often ruins or remains of wider portions. Therefore, archaeological artifacts generally occur as a discontinuous set of walls or columns detached from the original context. The absence of most of the original structural portions makes them much more vulnerable. Indeed, even if their current existing condition is an indicator of their equilibrium condition under gravitational loads, this condition is not sufficient to guarantee their preservation in the case of an unexpected earthquake. Furthermore, the cracking patterns and collapses make them even more vulnerable. For these reasons, the vulnerability of ruins should be addressed as regard to the possible failure mechanisms that can be activated by seismic actions. Accordingly, in this article a novel and targeted numerical tool for seismic vulnerability assessment of remains in archaeological sites, that considers collapse mechanisms occurrence as the main cause of masonry constructions being lost, is presented. Results of the numerical procedure proposed are compared with the results obtained by the canonical formulation of virtual works. Finally, the seismic vulnerability level of selected masonry constructions in the archaeological sites of Pompeii and Arpino (Italy) has been assessed by the use of this procedure.