Seismic resilience of existing RC dual-system buildings during the 2023 Kahramanmaraş earthquakes: a case study

This study investigates the seismic resilience of an existing reinforced concrete (RC) dual-system during the 2023 Kahramanmaraş earthquakes. The shear wall-frame dual building was designed according to the Turkish guidelines (TEC 2007) and experienced negligible damage during the earthquakes, whereas all neighboring buildings collapsed. The case study building is modeled in SAP2000® adopting a lumped plasticity approach. The 3D building model was subsequently subjected to pushover and nonlinear time-history analyses (NTHAs) using real ground motions recorded during the first and strongest mainshock of the Kahramanmaraş earthquakes (${M_w}$ = 7.7 Pazarcik earthquake). The results from the NTHAs indicate that the maximum inter-story drift (IDR) ratios on all floors of the case study building remained below the Immediate Occupancy performance level (IDR = 1.0%). Moreover, the dual-system building designed with TEC 2007 survived the earthquakes without damage, even when the design earthquake scenarios exceeded those considered in the new and more stringent TBEC 2018 (i.e. a 475 return period). The limited damage experienced by the RC dual-system building can be largely attributed to its high wall index (WI = 1.5% and 1.84%) and high average lateral stiffness index (H/T ≥45.3), which are above the minimum values (ρ = 0.6% and H/T ≥45) suggested in previous research. This study also highlights the critical importance of site-specific ground motion selection, particularly in the context of Hatay province, where the seismic demands exhibited significant variability and intensity. This study contributes to a better understanding of the resilience of RC shear wall-frame buildings in seismic zones.