Earthquake performance analysis of historical MelikSunullah Mosque minaret

In this thesis study, the seismic performance of the Historical Melik Sunullah Mosque Minaret, a significant example of Ottoman-era architectural heritage, has been investigated. The current condition of the structure was examined in detail along with its architectural and structural characteristics. The soil properties and material specifications of the building were identified, and a 3D structural model was developed using SAP2000 software based on original measured drawings obtained from the Malatya Regional Directorate of Foundations. A modal analysis was conducted to determine the dynamic characteristics of the structure, and the first natural vibration period was calculated as 0.669 seconds. Furthermore, the cumulative mass participation ratio exceeded 95% starting from the eighth mode out of a total of 20 modes, indicating that the dynamic behavior of the structure was sufficiently represented in the analysis. For seismic performance evaluation, a total of 11 real earthquake records including the 2023 Kahramanmaraş Earthquake in Türkiye were applied to the model. The analyses were performed using the Nonlinear Time History Analysis method, which allows the structural response beyond the elastic range to be considered, thus providing a more realistic representation of the behavior under seismic loads. The results showed that significant tensile stresses occurred particularly in the shaft region of the minaret, where brick masonry is present. This outcome is attributed to the modeling being based on the original historical material properties, rather than the upgraded materials used in the 2017 restoration. In reality, the brick portion of the shaft had been largely replaced with modern materials and higher-strength mortars during the restoration, while the base section made of natural stone remained mostly unaltered, with only surface-level repairs such as joint filling. Consequently, although the analysis indicated higher stresses in the shaft, post-earthquake field observations revealed cracking primarily at the base, reflecting the real-world effects of differential material intervention. This study emphasizes that a comprehensive seismic performance assessment of historical structures must account for both the original construction characteristics and any structural interventions introduced during restoration processes.