Modelling and Seismic Response Analysis of Existing Italian Residential RC Buildings Retrofitted by Seismic Isolation

The seismic performance of existing RC frame buildings seismically retrofittedby base isolation is examined. Two different types of isolation systemsare considered, i.e.: rubber-based and friction-based isolation systems,respectively. Two different performance levels are examined, namely:Global collapse prevention and Usability preventing damage. Seismic performanceis assessed by multi-stripe nonlinear time-history analysis, consideringearthquake intensity levels with return period ranging from 10 to100000 years. Results point out that seismic isolation works effectively inlimiting damage well beyond the design limit state level while it showsa limited margin with respect to collapse beyond the design limit statelevel