Experimental and numerical study on the application of the flat jack tests to masonry walls

Double flat-jack tests were performed on a brick masonry wall using a series of LVDT’s to monitor the distribution of displacements in the wall above the top flat-jack. The results allowed estimating: (i) the way the stress induced by the flat-jacks is distributed in the wall; (ii) the main direction of the joints openings/cracks that in fact extend to the sides of the flat-jack. The analysis of these results shows that actually a volume of wall larger than the one above the top flat-jack is directly involved in the test.A numerical simulation of the flat-jack test using a finite element code was also performed.