The earthquake in Van Province took place at 13.41 (with local time, GMT+3) on October 23, 2011 with a magnitude of 7.2 in Turkey. The earthquake with an approximate rupture duration of 50s occurred at 43.36 Eastern longitude and 38.75 Northern latitude at a depth of 10–15km below the surface of the earth, triggering an average displacement of 2 m in Northeast–Southwest direction. With Van’s Erciş Town constituting the epicenter, the earthquake was felt in the city center and surrounding villages, along with the nearby provinces of Erzurum, Ağrı, Mardin, Diyarbakır, Muş, Bitlis, Iğdır, Kars, Batman, Siirt and their respective towns. According to the data released by Republic of Turkey, Ministry of Environment and Urban Planning, 2288 buildings fully collapsed as a result of the earthquake. Analyzing the structural characteristics of the region, it is observed that urban centers are dominated by RC buildings, while mostly adobe structures prevail in the rural areas. The on-site technical investigations revealed that the damages were caused mostly by faulty concrete production, defects in reinforcement details and the poor quality of workmanship. In the study, impacts of the mentioned earthquake on the structures in the region and the underlying reasons were analyzed, and a number of recommendations were provided to prevent the repetition of similar flaws

This study investigates the pounding phenomenon by shaking table experiments on two scaled building models. Representing the situation where the seismic gap is insufficient, two building models are adjacently positioned on the shaking table, and pounding was investigated for harmonic and strong ground motion excitations. Displacement and acceleration responses were obtained to observe the pounding effect experimentally from video and accelerometer recordings, respectively. The Kelvin-Voigt Model consisting of spring and damper was used for numerical pounding analysis. The most critical parameters of the Kelvin–Voigt model, which are the spring stiffness (ks) and the damping, are calculated according to the coefficient of restitution (r) and were investigated and compared with harmonic experimental results. The obtained parameters, compatible with the harmonic experiments, were used to examine structural behavior under earthquake effect for the case where the building models are positioned for an insufficient seismic gap. For comparison, numerous numerical simulations were realized using different spring stiffnesses and coefficients of restitution. The study shows that when the coefficient of restitution is taken as 0.2 or 0.4, and the ratio of spring stiffness to shear stiffness (ks/k) is 1 or 5, reasonable results in numerical earthquake simulations can be obtained.

The structural safety of minarets is a critical issue, as their collapse during earthquakes poses severe risks to human life and nearby structures. However, there are no regulations considering their unique structural behavior. In the present study, this unique behavior is investigated by a comprehensive field reconnaissance conducted on masonry and RC minarets affected by the February 6, 2023, Kahramanmaraş Earthquakes. This investigation focused on identifying the underlying causes of minaret damage and collapse, with particular attention to failure mechanisms, material deficiencies, structural design shortcomings, and detailing weaknesses. In addition to the recorded high ground accelerations, the study revealed that the causes of minaret collapse and damage were widespread structural defects and design practices that inadequately reflect their unique seismic behavior. Furthermore, on a representative masonry minaret model, modal and time-history analyses were performed to investigate dynamic behavior. Another noteworthy finding highlights that near-fault effects are significantly influential in the collapse direction of RC minarets. Finally, design suggestions for future regulations specialized for the structural behavior of minarets and mitigation strategies are presented, to prevent similar damage and collapses in future earthquakes.