Field Validation of Nonlinear Dynamic Simulation for Plan-Irregular RC Buildings: Insights from the 2024 Hualien Earthquake

Abstract

This study evaluates the post-earthquake damage of a 17-story plan-irregular reinforced concrete (RC) building damaged during the 2024 Hualien earthquake. A three-dimensional numerical model was constructed in ETABS, utilizing nonlinear component characteristics derived from the mechanics-based Seismic Evaluation of RC Building (SERCB) framework to execute nonlinear dynamic time-history analysis (NDTHA). The actual triaxial ground motion records from the 3 April 2024 earthquake were applied as the seismic input. To correlate analytical outcomes with physical seismic damage, a displacement-based ductility development index (D) was adopted to quantitatively associate simulated plastic hinge responses with field-observed damage states ranging from Slight (DS I) to Collapse (DS V). Post-earthquake reconnaissance revealed that structural damage was primarily concentrated in the perimeter RC shear walls between the 1st and 6th stories. The predicted wall damage states spanned from Moderate (DS II) to Severe (DS IV), whereas the primary beam–column frame exhibited only Slight damage (DS I). Quantitative comparison demonstrates exact damage state match rates of 63.6% (7/11) for Frame 1 and 71.4% (5/7) for Frame 2, with all remaining discrepancies bounded within a minor one-class margin. These analytical results show high consistency with field observations, confirming that NDTHA incorporating SERCB-based plastic hinge modeling can effectively reproduce the nonlinear seismic behavior and localized damage distribution of torsionally irregular RC structures. The findings extend traditional laboratory-scale component validation to full-scale building damage reconnaissance, providing robust empirical evidence for cross-validating physical seismic damage against dynamic simulation predictions.