Valutazione prestazionale di edifici in muratura in presenza di interventi di miglioramento sismico

In this paper the performance-based assessment of a masonry building strengthened with fibre reinforced polymers to improve seismic resistance is carried out. At this aim, a nonlinear static procedure was used to estimate maximum lateral displacement, to control the acceptance criteria of unreinforced masonry walls and to keep them within tolerable limits at each performance level. These multi-level objectives were pursued with a procedure based on the adaptive pushover, the Capacity Spectrum Method and the Inelastic Demand Response Spectra. At first, a procedure based on the minimum error condition on the natural frequencies, mode shapes and modal forces was used to calibrate the finite element model. Then pushover analysis was carried out with an adaptive load pattern which allows for the redistribution of load as an effect of non-uniform yielding. An incremental non iterative procedure to correlate the earthquake intensity levels and performance levels defined by the acceptance criteria was used. Finally, the correlation between earthquake intensity levels and performance levels both for unreinforced and for the FRP strengthened masonry building was investigated.