RISCHIO SISMICO DI AREE URBANE COMPLESSE: PROGETTO SISMED

During last year’s seismic risk assessment on a territorial scale has evolved with important changes for the increase of techniques and scientific knowledge and for the exceptional development of data-bases for the collection and management of large amounts of data. The Italian building heritage is largely previous the introduction of anti-seismic regulations, it is composed mainly of historic buildings and structures built during the economic boom of the 60s. The objective of the survey is to define the seismic risk of the city of Florence, a complex area for exceptional architectural heritage and for its imposing dimensions. Starting from a deep knowledge of the seismic risk of the subsoil, little we know about the vulnerability, only 30% of the existing buildings have been tested by the "great earthquake" of 1895, and 97% is designed and built before the seismic classification of the territory realized only in 1982. The subject of the research projects Sismed and Sismed II is the analysis of the building heritage. The research is divided into two phases, the first of classification of the structures, followed by a second of on-site surveys. The buildings have been cataloged with a GIS data-base and classified by its main characteristics. Finally, with a sample strategy, a series of representative structures were selected. on these structures, instrumental measurements and surveys were made, to obtain a real estimate and to elaborate a map of the seismic vulnerability of the city.