Seismic protection of masonry buildings by reversible mixed techniques based on fiber composites

In this paper the behaviour of unreinforced masonry walls strengthened by techniques based on Fiber Reinforced Plastic (FRP) and Fiber Reinforced Cement Matrix (FRCM) is investigated. At first, static and dynamic identification procedures are applied to calibrate the finite element model. Then, a nonlinear static procedure is 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 are pursued with a procedure based on the adaptive pushover, the Capacity Spectrum Method and the Inelastic Demand Response Spectra. Then, pushover analysis is carried out under both adaptive and invariant load patterns, which allows for the redistribution of load as an effect of non-uniform yielding. An incremental non iterative procedure is used to correlate the earthquake intensity levels and the performance levels defined by specific acceptance criteria. Finally, the correlation between earthquake intensity levels and performance levels for both unreinforced and reinforced masonry building is investigated.