Seismic behaviour of masonry cross vaults in Medieval churches

Recent experiences have shown that masonry vaults in Italian churches are prone to damage due to seismic loading. Understanding the seismic response of these structures is therefore crucial to preserving the architectural and cultural significance of this heritage. This study is part of the research project "Seismic Risk Management for the Tourist Valorization of Historical Centers in Southern Italy GENESIS" and aims at assessing the seismic response of masonry cross vaults, characteristic of Italian Medieval churches. Using a case study of a notable Italian cathedral in Caserta, a representative masonry cross vault is defined and analyzed through nonlinear numerical simulations. In particular, the diaphragm effect of the vault is examined by applying progressively increasing horizontal displacement to two sup-ports until collapse, allowing for the evaluation of the capacity, stiffness degradation and collapse mode due to earthquake-induced damage. As a preliminary step towards a laboratory test on a large-scale prototype, a parametric investigation is conducted, varying the vault and rib thicknesses and considering the influence of walls filling the lateral arches. The results show a relationship between the vault structural features and its load-bearing capacity and collapse mechanisms, which will guide the design of the pro-totype for testing.