Finite element modeling of a low-rise RC structure for seismic assessment: Validation via operational modal analysis

Türkiye has a large building stock requiring seismic performance evaluation. Law No. 6306, enacted in 2012, governs the identification and renewal of risky structures. In this context, a seismic assessment was conducted on a four-story reinforced concrete building. A finite element model was developed, and theoretical modal analysis yielded a fundamental vibration period of 1.220 seconds. Due to this high value, an operational modal analysis was performed, revealing a period of 0.240 seconds. Comparison with the regional horizontal elastic design spectrum indicated that neglecting the stiffness contribution of infill walls in the model could lead to seismic loads approximately 5.1 times higher than realistic values, which may result in a significantly inaccurate performance assessment.