EVALUATION OF THE INTER-STORY ISOLATION SYSTEM APPLIED TO AN EXISTING RC SCHOOL BUILDING

Inter-story Isolation System (IIS) is an interesting technique for the mitigation of the seismic risk of buildings. In existing buildings, this technique can also be effectively used, when properly designed, to add extra stories while reducing the seismic response of the structure, representing an innovative retrofitting strategy. Therefore, IIS is particularly advantageous when it is desired to both increase the volume of the building and improve its seismic behaviour. In this paper, the IIS is used to rise an existing reinforced concrete school building, while improving its overall seismic behaviour. First, a specific superstructure is chosen and the optimization approach for deriving the optimal IIS parameters is presented. Then, based on the optimal results obtained, the IIS is designed, and its effectiveness is investigated by performing Time History analysis, using a set of spectrum-compatible natural records and a fiber modelling of the structure, and comparing the results obtained with and without the IIS.