Field Observations and Numerical Modeling of the Collapse Mechanism of the Habibi Neccar Mosque During the 2023 Kahramanmaras Earthquakes☆

Abstract

The seismic behavior and collapse mechanism of the Habibi Neccar Mosque-recognized as the first mosque in Anatolia and completely destroyed during the 6 February 2023 Kahramanmaras, earthquakes-were investigated through an integrated methodology comprising field observations, structural modeling, and advanced numerical analyses. The structure was modeled using a macro-scale finite element approach with SOLID65 elements in ANSYS, incorporating the Willam-Warnke failure surface to simulate the nonlinear behavior of masonry components. Material properties were derived from experimental studies on regional stone types and engineering correlations. The first three vibration modes obtained through modal analysis revealed dominant translational and torsional behavior, with the first-mode frequency computed as 5.26 Hz. Pushover analyses indicated direction-dependent lateral load capacities: approximately 18,000 kN in the X direction and 14,000 kN in the Z direction. Nonlinear time-history analyses using unscaled ground motion records from the epicentral region demonstrated that the structure entered a collapse mechanism at a dome displacement of +/- 15 mm, with maximum base shear forces reaching 10,000 kN. The dynamic strain distributions confirmed the progressive damage initiated at the dome-arch interface, followed by sequential failure of the vaults, portico, and bearing walls. These results exhibited strong agreement with post-earthquake field observations, validating both the structural modeling strategy and the defined material parameters. Furthermore, the analytical outcomes were found to be consistent with empirical displacement-based collapse limits reported in previous studies. This research emphasizes the importance of displacement-based nonlinear analysis methods in assessing the seismic vulnerability of historical masonry mosques. The presented methodology and findings are expected to serve as a reference framework for the structural evaluation, retrofitting, and restoration of heritage structures located in high seismicity regions.