عنوان مقاله [English]
نویسندگان [English]چکیده [English]
The present study investigates the seismic performance of reinforced concrete moment frame system retrofitted with different steel bracing systems. Two types of structural combinations including concentric steel bracing system and steel mega bracing system were used in two types of structures with different numbers of stories. These two structures which are designed by 5 and 10 story reinforced concrete moment frame system have poor lateral stiffness. They were considered to compensate for the limitations of drift regulations in areas with high seismic risk and life safety performance level. Then, these frames are improved by concentric steel bracing system and mega bracing system. In this study, the nonlinear static (pushover) analysis was used to evaluate the performance of the structure under the influence of ground motions. Also chord rotation, story drift and base shear were used to compare the response of the improved structure. It was shown that the steel mega bracing system and the concentric steel bracing system are respectively the best types of steel bracing systems for upgrading and retrofitting the structures in terms of drift control regulations, the amount of base shear, the number of plastic hinges, the number of collapse elements and the economic issues.