Experimental characterization of out-of-plane seismic response of strengthened three-leaf stone masonry walls by shaking table test

The results of an experimental campaign on eight full scale three-leaf masonry walls tested on shaking table are presented. The walls were tested under out-of-plane dynamic actions. The influence of retrofitting interventions is compared considering grout injection, transverse tying and a combined solution of the two techniques. Results showed the enhancement in the performance of the masonry and the modification of the brittle mechanisms, due to the counteraction of separation of leaves given by ties, the homogeneity and compactness of the inner core given by grout injections, and the improvement of the overall behavior given by the combination of the two techniques. Failure mechanisms, acceleration amplifications and effect on local displacements, are compared and discussed.