ZERIHUN TALE BIZUNEH2026-02-172021-10-22https://etd.hu.edu.et/handle/123456789/873A reinforced hollow concrete block masonry walls constructed by assembling masonry units, and it was the key structural element widely used to resist lateral loads in masonry buildings. Unreinforced hollow concrete block Masonry wall rapidly fails because of lateral load like an earthquake. Hence this study attempts to evaluate responses of a reinforced and unreinforced fully grouted hollow concrete block masonry wall, select the best walls based on differing their aspect (H/L) ratio, horizontal and vertical reinforcement ratio, and spacing. Also, know the behavior of reinforced and unreinforced fully grouted hollow concrete block masonry wall under lateral load and determine its percentage effectiveness. The study was conducted using finite element ABAQUS software for which a total of 24 masonry wall models were considered. For validation of the finite element method, reinforced masonry walls experimentally worked by M. Hany (2016), and the experimental results compared with the numerically modeled. The comparison of the results indicated that both experimental and numerical results agreed very well. After the validation, the effect of seismic load on reinforced and unreinforced fully grouted hollow concrete block masonry walls investigated by the quasi-static method. The comparison for ultimate load carrying capacity, stiffness degradation, and displacement ductility of each investigation parameter are carried out from the comparative analysis. It was found that the aspect ratio 1.39 wall vertical reinforcement ratio increases from 0.26% to 0.36%, the ultimate strength increase by 15.344% for push and 14.578% for pull direction. And also, the vertical reinforcement spacing increases the Ultimate strength of the wall decrease. The Ultimate shear resistance of the wall is reduced by 17.21% for push and 14.25% for pull direction for in-plane load when the spacing of Ø16 vertical reinforcement increases from 200mm to 400mm. The aspect H/L ratio increase from 1.39 to 1.95 the ultimate strength decrease by 38.15% for push direction and 41.89% for pull direction. Generally, aspect ratio, vertical reinforcement spacing, and vertical reinforcement ratio variation highly influence hollow concrete masonry wall seismic performance relative to horizontal reinforcementenFinite Element SimulationHorizontal reinforcementLateral Displacement Masonry wallQuasi-staticVertical reinforcementThesis