Performance of a multi-story reinforced concrete flat plate slab building with and without steel bracing under Seismic loading

This study evaluates the seismic performance of multi-story reinforced concrete flat plate slab buildings with and without steel bracing. The structural behavior of 4, 6, and 8-story buildings under seismic loading was analyzed using ETABS software, incorporating data from Halabjah, Chi-Chi, and Kobe earthquakes. Nonlinear dynamic and pushover analyses assessed parameters such as story drift, roof displacement, and strain responses. Steel bracing configurations (center core, exterior corner, and exterior side) significantly improved seismic resilience by enhancing lateral stiffness, reducing displacement, and controlling drift. Results showed center-core bracing as the most effective configuration, achieving displacement reductions up to 52.32% and drift reductions up to 59.98%. Bracing also minimized the formation of plastic hinges, enhancing energy dissipation and structural integrity. The study highlights the impact of brace placement, building height, and earthquake intensity on seismic performance. At the same time, shorter buildings exhibited more pronounced benefits and taller structures required optimized bracing strategies to increase flexibility and lateral force demands. These findings emphasize the necessity of steel bracing for improving seismic safety and resilience in reinforced concrete buildings, particularly in earthquake-prone regions, and provide insights for future seismic design and retrofitting practices.