Quasi-static test on half-scale modern unreinforced masonry building with plan irregularity

Abstract Unreinforced masonry structures are a significant percentage of the global building stock and are often vulnerable to seismic events due to their inherent structural weaknesses and limited deformation capacity. Although seismic codes promote regularity in structural design, achieving this in unreinforced masonry buildings is often a challenging task. Despite extensive research using shake table tests, quasi-static testing of unreinforced masonry buildings remains limited, particularly in the presence of plan irregularity and rigid diaphragm. The present study addresses this research gap by investigating the seismic response of a half-scale, two-story, unreinforced masonry building with plan irregularity through cyclic quasi-static testing. The experimental campaign presented here shows the findings from two tests, including dynamic identification. The first test indicated torsional amplification and rocking-induced wall detachment during the pre-peak response. These results prompted modifications to the experimental setup, including the addition of extra weight to prevent overall rocking and the repairing of the boundary interface to re-establish structural integrity for subsequent testing. The initial results highlight the influence of plan irregularity within the pre-peak behaviour and provide a basis for further exploration in the seismic assessment of irregular, unreinforced masonry buildings.