Seismic Performance of Steel Structures with Buckling Restrained Brace under Near and Far-Fault Earthquakes

Document Type : Original Article


Faculty of Civil Engineering, K. N. Toosi University of Technology, Tehran, Iran



Iran is located on the Alpine-Himalayan seismic belt and severe earthquakes have occurred in Iran during the past centuries. The existence of many steel structures in Iran and the need to strengthen them is one of the most important issues in Iran today. Modern braces are one of the best methods of seismic improvement of the structure, and the BRB system has a good performance for the seismic improvement of the structure. Therefore, in the present paper, we try to model steel structures with 3 and 6-story with SAP2000 and ABAQUS. Then the BRB are placed in the models and analyzed by the time history method. The earthquakes used in analyses are in far-fault (El Centro) and near-fault (Kobe) zones. Validation of the models was done with the paper of Lin et al. (2024) on a 6-story structure. Finally, the displacement and acceleration of frames with BRB systems are compared with steel moment frames (SMF). The results show that increasing the ratio of span loading to story height (w/h index) reduces the displacement and acceleration, so the w/h index has an invert relationship with the displacement and acceleration parameters in the structure. The BRB system has the greatest effect on the displacement and acceleration parameters in the far-fault and near-fault zones, respectively. The BRB system reduces displacement under El Centro and Kobe earthquakes by 81.08% and 72.26%, respectively, and reduces acceleration under El Centro and Kobe earthquakes, it becomes 41.7% and 44.54%, respectively.