AN APPRAISAL OF BASE ISOLATION FOR LARGE MONUMENTAL BUILDINGS

Traditional techniques for improving the seismic performance of buildings are based either on the increase in strength or in ductility or, sometimes, of both at the same time. This approach, however, can lead to interventions often deemed as too invasive on heritage buildings. An interesting alternative approach consists in the seismic base isolation of this type of buildings. This modern technique acts rather reducing the seismic energy fed into the structure, rather than trying to forcibly increase its strength or its ductility with local reinforcements. The aim of this work is related to the appraisal of available base isolation techniques with reference to the application to large monumental buildings, where several peculiar aspects have to be considered due to the building age, the urban context around these buildings, the remains of previous constructions these buildings might have been built over. All aspects complicating choice of the isolation system and the positioning of the isolation plane. Furthermore, in this work a base isolation intervention exploiting a classical technique of creating the isolation plane is designed and compared with a new proposal that seeks to obtain the isolation plane several meters below the building foundations.