Seismic vulnerability of worship buildings: the case study of Florentine Churches

As is well known, the building heritage of countries bordering the Mediterranean basin is subjected to considerable seismic risk; among these countries, Italy also has one of the richest cultural heritages in the world. For this reason, a series of initiatives have been implemented in Italy in recent years, by interventions at both regulatory and research level, aimed at safeguarding constructions having historical and architectural significance. From a technical point of view, minimally invasive methods have been proposed in order to reduce seismic vulnerability while respecting the original characteristics of the structure; at the same time, a series of investigation methods have been developed, having often a speedy character given the vastness of buildings to be investigated. These methods allow analysing and comparing the data and vulnerability levels of similar structures, thus permitting compilation of a database that is the starting point for guiding decision-making processes and allocation of resources for the protection of historical buildings. Among the various structural types, worship buildings have intrinsic characteristics that make them more vulnerable than other building types. Moreover, they often contain assets (statues, paintings, frescoes, etc.) of considerable cultural and artistic value. The proposed work presents the results of an investigation involving eighty-nine masonry churches in the city of Florence. The study takes into particular consideration the exposure of the investigated buildings, so providing indications to define possible intervention strategies and priorities, accounting both for the buildings structure and the value of goods housed within them.