Enhancing Seismic Performance of Multi-story Steel Buildings Using Inner Mega Braced Frames

Abstract

damage to buildings. In this study, a multi-story steel building is designed using the ETABS v16 software under vertical loads only. Subsequently, seismic performance was enhanced by employing five different Mega braced frames (MBFs) systems in two cases: in the first case, the five bracing systems are placed within a frame located 6 meters away from the outer frame, while in the second case; the bracing systems were placed within a frame located 12 meters away from the outer frame. The building was then analyzed using nonlinear time history analysis with SAP 2000 V20 software, utilizing seismic data from the El-Centro earthquake available in SAP 2000 V20. The results were compared based on various parameters such as maximum roof displacement, maximum inter-story drift ratio, and maximum base shear. The findings demonstrated an improvement in the building's response, in the first case maximum roof displacement reduction ranging from 36.08% to 48.29% in both directions, and from 36% to 44% for maximum roof displacement in the second case. Maximum inter story- drift ratio also reduced by percentages ranging from 25% to 46% in the first case and 25% to 39% in the second case. From the analysis results, it is evident that the best pattern in the first case is pattern5, while in the second case pattern4 is the best.