Comparative Seismic Assessment of Steel Moment-Resisting Frames Using Real and Artificial Spectrum-Matched Records under Multiple Soil Conditions

This study investigates the seismic response of steel moment-resisting frames (MRFs) using linear time-history analysis (LTHA) to evaluate the influence of real and artificial spectrum-matched ground-motion records under multiple soil conditions. Three archetype buildings—3-, 9-, and 20-story—were modeled according to the SAC Steel Project (FEMA 355-C Appendix B) and analyzed using SAP2000® to assess their comparative performance under different spectral inputs. The analysis employed three types of seismic spectra: The Elastic Spectrum (ES), Reduced Turkish Earthquake Code (TEC-2018) Spectrum, and Reduced ASCE Spectrum across four local soil classes (ZA–ZD). A total of 252 earthquake ground motions, including real and artificial records, were used. The results revealed that artificial records achieved smoother spectral compatibility and more stable base shear predictions, whereas real records induced higher variability owing to their natural frequency content and phase characteristics. This divergence was most significant in softer soils (ZC and ZD), with base shear variations of up to ±35%. The findings highlight the need to integrate both record types into seismic assessments and contribute to the advancement of performance-based earthquake engineering approaches.