Regional Spectrum-Based Seismic Performance Assessment of Historical Masonry Minarets and Observed Structural Damage After the 2023 Türkiye Earthquakes

The Kahramanmaraş-centered earthquakes of 6 February 2023 (Mw = 7.7 and Mw = 7.6) caused widespread damage to historical masonry minarets across 11 provinces (Kahramanmaraş, Hatay, Adıyaman, Malatya, Gaziantep, Kilis, Şanlıurfa, Adana, Osmaniye, Diyarbakır, and Elazığ) in southeastern Türkiye. This study evaluates the seismic performance of a representative masonry minaret model using site-specific design response spectra derived from the current national seismic hazard map for each province. Finite element analyses were performed under various earthquake load combinations, and stress distributions and displacement responses were comparatively assessed. The results reveal pronounced regional variations in seismic demand. For instance, the design spectral acceleration (SDS) and corresponding shear stress (S12) values in Gaziantep are approximately four times higher than those in Kilis, indicating a substantially greater seismic demand. Similarly, maximum tensile and compressive stresses consistently reach their highest levels in Gaziantep, Elazığ, and Hatay, whereas Kilis and Şanlıurfa exhibit the lowest stress values across all load combinations. In addition to numerical analyses, post-earthquake field observations from 29 historical minarets were evaluated, and typical damage patterns were identified. A strong correlation was observed between analytically predicted stress concentration zones, particularly at the transition segment, balcony level, and upper body, and the actual damage documented in the field. The study demonstrates that site-specific seismic parameters play a decisive role in the structural response of masonry minarets and that regional differences must be explicitly considered in seismic assessment and conservation strategies. These findings provide a quantitative basis for prioritizing strengthening interventions and improving the resilience of historical structures against future earthquakes.