Shear-compression tests of URM walls: Various setups and their influence on experimental results

Current design codes provide empirical equations for the drift capacity of unreinforced masonry (URM) walls that are based on results of quasi-static cyclic shear-compression tests. Yet different experimental campaigns have used various approaches of imposing fixed-fixed boundary conditions at the wall top which may affect the test results. This article investigates, by means of numerical simulations, the influence of experimental setups on the force and drift capacities of in-plane loaded URM walls subjected to double-fixed conditions. It is shown that controlling the shear span or the top rotation while keeping the axial force constant leads to very similar results. Controlling the axial elongation at the top of the wall results for walls subjected to a small axial load ratio in an increase and for walls subjected to a large axial load ratio in a decrease in axial load with increasing drift demands. Testing a wall with half the height applying cantilever boundary conditions is not recommended as the stiff loading beam at the wall top changes the failure mode and leads to significantly larger drift capacities.