Seismic Performance Assessment of Reinforced Concrete Buildings Using Nonlinear Static Pushover Analysis

Abstract

Seismic assessment of reinforced-concrete (RC) buildings requires understanding behavior beyond the elastic range. Linear analysis cannot reveal yielding or capacity loss; nonlinear dynamic analysis is costly, and few studies report pushover output for a regular frame and an existing building. This study applies nonlinear static (pushover) analysis to both. Two three-dimensional models were analysed: a regular four-story frame and an existing three-story Libyan building. Models were developed in SAP2000 with nonlinear hinges assigned to beams and columns. Monotonic lateral loading was applied until a mechanism formed. Capacity curves were converted to capacity spectra following ATC-40. Evaluation used base shear, roof displacement, hinge states (Immediate Occupancy, Life Safety, Collapse Prevention) and the performance point. The frame peaked at 483.87 kN, then lost capacity abruptly, whereas the building peaked at 2256.583 kN, degrading gradually, with a performance point at 48.973 mm and 1786.369 kN. It contributes a documented workflow and comparative results.