Seismic performance of multi-storey steel frame buildings with various configurations of eccentric braced

Department of Civil Engineering, Faculty of Engineering, Universitas Andalas, Padang, Indonesia

^* Corresponding author: ridho@eng.unand.ac.id

Abstract

Structural stability and strength are essential to ensure adequate seismic performance particularly for Eccentrically Braced Frames (EBF) by providing high elastic stiffness, ductility, and energy dissipation. This study analyses the optimal configuration of EBF system for industrial buildings using nonlinear static pushover analysis. Four structural models were analyzed: one unbraced as a baseline and three EBF configurations with varying bracing placements, considering both service and earthquake load conditions. Fragility curves were then derived from capacity curve, incorporating key parameters such as yield and ultimate roof displacement. The findings indicate differences in seismic performance among the models. Model-A shows early onset of damage and collapse, reflecting limited ductility. Model B performs better but less reliable at higher damage states. Model C and D demonstrate adequate resilience, with delayed damage progression and higher ultimate displacement capacity. It was concluded that the most optimum eccentric bracing configuration is model B (model with bracing installed on all exterior sides of the structure) because it is suitable for service-level performance, while model D (model with bracing installed on center of exterior of the structure) provides the greatest safety against collapse, making it the most reliable for building in high seismic regions.