Numerical interpretation of the experimental results obtained with flat-jack tests on a brick masonry wall

Four numerical simulations of the double flat-jack test on a historic brick masonry wall, using a finite element code, are presented. The aim is to show which of the simulations best fit the experimental results, achieved measuring the strain distribution in the area between the two flat-jacks and also in the area above the upper flat-jack. The numerical and experimental results allow to compare: i) which is the strain distribution induced by the flat-jacks during the test; ii) which are the main directions of the local compressive and tensile stresses leading to cracks; iii) which of the chosen numerical simulations gives the best fit. Finally, these results show which is the volume of the masonry wall really involved in the test.