en Research Paper Research Paper <font size="1" face="Times-Italic"><font size="1" face="Times-Italic"><p align="left">Confined masonry buildings are used in rural and urban areas of Iran. They performed almost satisfactory</p><p align="left">during past moderate earthquakes of Iran. There is not a methodology in Iranian Seismic Code (Standard 2800-3rd</p><p align="left">edition) to estimate their capacities quantitatively. In line with removing this constraint, an attempt is made to study</p><p align="left">in-plane behavior of two squared confined masonry walls with and without opening by using a numerical approach.</p><p align="left">These walls are considered based on Iranian Seismic Code requirements. Finite element 2D models of the walls are</p><p align="left">developed and a pushover analysis is carried out. To model the non-linear behavior of the confined masonry walls, the</p><p align="left">following criteria are used: (1) The Rankine-Hill yield criterion with low orthotropic factor to model the masonry</p><p align="left">panel (2) The Rankine yield criterion to model reinforced concrete bond-beams and tie-columns (3) The Coulomb</p><p align="left">friction criterion with tension cutoff mode to model the interface zone between the masonry panel and reinforced</p><p align="left">concrete members. For this purpose, the unknown parameters are determined by testing of masonry and concrete</p><p align="left">samples and by finite element analysis. Comparing the results show that the initial stiffness, the maximum lateral</p><p align="left">strength and the ductility factor of walls with and without opening are different. Also, the severe compressed zones of</p><p align="left">the masonry panels within the confining elements are found different from what are reported for the masonry panels</p><p align="left">of infilled frames by other researchers. This study shows that a further investigation is needed for estimating capacity</p><p align="left">of confined masonry walls with and without opening analytically and experimentally. Also where openings, with</p><p align="left">medium size are existed, the confining elements should be added around them. These issues can be considered in the</p><p align="left">next revisions of Iranian Seismic Code.</p></font></font> Confined Masonry, Bond-Beams, Tie-Columns, In-Plane Behavior, Capacity Curves, Interface Modeling 49 60 http://ijce.iust.ac.ir/browse.php?a_code=A-10-897-2&slc_lang=en&sid=1 Sassan Eshghi s.eshghi@iiees.ac.ir 180031947532846006054 180031947532846006054 Yes Khashaiar Pourazin pourazin@iiees.ac.ir 180031947532846006055 180031947532846006055 No