Influence of coupling on the displacement capacities of URM piers – comparison of experimental results with existing recommendations

In existing European recommendations the drift capacity of unreinforced masonry (URM) piers is estimated as a function of the failure mode, aspect ratio and/or axial load ratio. The empirical relationships are based on a set of results from quasi-static cyclic tests on single URM piers, which were tested simulating either double-fixed or cantilever boundary conditions. In modern URM structures, the URM piers are often connected by reinforced concrete (RC) slabs which provide enough stiffness and strength to impose a certain rotational restraint to the piers. In this paper we determine typical boundary conditions and apply them within a series of quasi-static cyclic tests of URM piers. Some preliminary results are presented and compared to existing recommendations for modern European masonry. Differences between the experimental results and the recommendations are reported and tendencies discussed.