SEISMIC PERFORMANCE EVALUATION OF BRICK MASONRY SHEAR WALLS CONSTRUCTED IN STONE DUST MORTAR

An experimental study to evaluate the seismic performance of unreinforced brick masonry (URBM) shear walls constructed in cement, sand and stone dust mortar being widely used in Northern Pakistan is presented. In-plane shear-compression tests were carried out on twelve walls, using quasi-static cyclic loading. Testing set produced double bending curvature in walls. The effect of aspect ratio and pre-compression levels on various parameters used to quantify seismic performance is examined. Experimental work showed that walls with medium to high aspect ratios failed in diagonal tensile shear failure mode while squat walls failed in diagonal shear followed by bed-joint sliding. The diagonal tensile shear strengths of the walls determined from experimental work were then compared with Turnsek and Sheppard equation used to determine diagonal tensile shear strength of URBM walls. Influence of the pre-compression level on the lateral displacement ductility, drift ratio and equivalent viscous damping of the walls is discussed. Finally, drift ratios for performance levels corresponding to various damage levels, for unreinforced brick masonry walls, are proposed on the basis of experimental results.