Effects of vertical stresses and flanges on seismic behavior of unreinforced brick masonry

Lateral in-plane response plays crucial role in seismic behavior of masonry structures. The aim of this article is to experimentally investigate the effects of vertical stresses and flanges (transverse walls) on the lateral in-plane response of the unreinforced brick masonry (URBM) walls. The experimental work included lateral in-plane quasi-static cyclic tests on full-scale walls (both with & without flanges). The vertical stresses resulting from typical single and two story unreinforced masonry buildings were simulated on full scale URBM walls. Flanges were introduced at both ends of the in-plane wall in single direction. In essence, the lateral in-plane stiffness & strength, deformability and energy dissipation of the two classes of walls are compared and the differences are quantified to help understand the effects of flanges on the in-plane response of masonry walls. The resulting damage mechanism and failure modes for each case are critically analyzed. The experimental results indicate that both vertical stresses and flanges incorporation significantly improved seismic response of URBM walls. In addition, the participation of flanges is critical in both vertical stress conditions.