Regional building damage assessment in 2023 Turkey-Syria earthquake doublet based on strong-motion records

An earthquake doublet with magnitudes Mw7.8 and Mw7.6 struck southeastern Turkey on February 6, 2023, causing widespread loss of life and property. To evaluate the seismic damage across 11 affected provinces, we conducted a comprehensive analysis of strong motions and building damage. Specifically, we analyzed the statistical and spatial ground motion intensity measures, along with special characteristics of near-fault pulse-like ground motion. Based on nonlinear seismic analysis, fragility functions were developed to assess the damage states of buildings, where five types of structures are adopted to represent the most common buildings and infrastructures in Turkish cities. Furthermore, the spatial distributions of ground motion intensities and building damage states were validated using official damage reports and field surveys. Results indicate that our model aligns well with these reports and surveys, provided that sufficient seismic records are available. Extensive building damage in the earthquake is primarily attributed to the high intensities of strong motion, construction quality and building resonance, with additional contributions from earthquake-induced geological and geotechnical hazards. Moreover, near-fault regions experienced greater damage due to stronger pulse-like ground motions, fault displacements, and geohazards, all closely associated with fault ruptures. By providing insights into special seismic impacts in near-fault regions and the real characteristics of ground motions, this work contributes to the advancement of ground motion modeling, seismic risk analysis, and disaster management, ultimately supporting the development of more resilient communities.