Analytical prediction of the seismic resistance of masonry buildings retrofitted by Steel Fiber Reinforced Mortar coatings

An extensive experimental program has been performed in the last years at the University of Brescia to show the effectiveness of the in-plane seismic strengthening or repairing of existing masonry buildings by Steel Fiber Reinforced Mortar (SFRM) coatings. In particular, the tests on a full-scale hollow clay block masonry building showed the applicability of the retrofitting technique on the external surface of the structure only. An analytical model already developed and validated is briefly presented in this article and applied to the building experimentally tested. Particular attention is paid to the simplified schematization of the masonry piers based on the fracture lines expected before and after retrofitting. The effectiveness of the analytical model in predicting the seismic resistance of the building is assessed by comparing the analytical results with those obtained from the experimental test. Finally, the analytical model is applied to a real two-story residential building made of concrete hollow units to perform the seismic verification of the structure. The analytical prediction of the global seismic resistance of the building is compared with that obtained from a non-linear static analysis carried out with the finite element program Midas FEA. The results of the comparison will further prove the reliability of the proposed analytical model.