Post-earthquake assessment and strengthening of the historical Elbistan Museum located at the epicenter of the Mw 7.6 Kahramanmaraş earthquake

Abstract The Elbistan Museum, located near the epicenter of the Mw 7.6 Elbistan earthquake, was affected by the 6 February 2023 Kahramanmaraş earthquake sequence (Mw 7.7 Pazarcık and Mw 7.6 Elbistan), with the most severe structural damage occurring during the second mainshock. Diagonal tensile and shear cracks appeared on interior masonry walls, while the exterior façades showed surface cracking, material separation, and partial stone detachment. This study investigates the observed damage through detailed field surveys and digital twin modeling to evaluate the museum’s structural performance. During the 2017 restoration process, the building underwent structural retrofitting interventions. Independent internal steel frames were introduced to carry live and dead loads from visitors and intermediate floors, thereby reducing vertical load demand on the masonry walls. In addition, a continuous steel ring beam was installed at the roof level to provide rigid diaphragm action and enhance global stiffness. Three-dimensional finite element (FE) analyses were performed in ABAQUS using a macro-modeling approach. Linear modal and response spectrum analyses were conducted to evaluate the global dynamic characteristics, followed by nonlinear time-history analyses to assess seismic performance under strong ground motion. The results demonstrated that the steel ring beam significantly improved the structural response. Compared with the Unreinforced Masonry Model (URM), the dominant period decreased by approximately 9%, while stresses and roof displacements in the Steel Roof-Diaphragm Model (SRDM) were reduced by 34% and 41%, respectively. Furthermore, micro-model analyses were carried out to evaluate the effectiveness of proposed clamp and dowel reinforcements for wall reconstruction. The strengthened walls exhibited 28% lower out-of-plane displacements and no material detachment, indicating more stable behavior. These findings confirm that the proposed technique provides an effective strengthening solution for thin, ashlar-faced rubble masonry walls such as those of the Elbistan Museum.