Numerical assessment of a slender structure damaged during October 30, 2020, Izmir earthquake in Turkey

The minarets, which have a tall and slender structure, are quite vulnerable to dynamic forces, i.e. earthquakes and winds. In mainly concrete minarets, since the bond between the concrete blocks is provided by only mortar, the damages caused by high tensile stresses may emerge. This study aims to simulate the behaviour of the concrete Selimiye minaret damaged during the Izmir (Seferihisar-Samos) earthquake on October 30, 2020. The nonlinear finite element model of the Selimiye minaret is created using the Concrete Damage Plasticity failure model. In the nonlinear time history analyses, the Izmir earthquake records obtained from the Bayrakli station, located the closest to the minaret, are used. The damages occurring in the transition segment of the minaret are verified with the finite element method. This study also aims to strengthen insufficient concrete minarets with an innovative, cost-effective, and better workability method. The proposed strengthening method is based on a Fabric Reinforced Concrete Mixture. Finite element models are strengthened from the inner surface using Fabric Reinforced Concrete Mixture composites reinforced with glass and steel fibers. As a result of the finite element analyses, it is concluded that the concrete minarets can be strengthened from the inner surface with the Steel Fabric Reinforced Concrete Mixture method in safety. In addition, with a parametric study, it has been determined that partial strengthening applications, which are more economical and aesthetic, can be more effective on structural performance than full strengthening applications.

Automated summary

The study aims to simulate the behavior of the concrete Selimiye minaret damaged during the Izmir earthquake in 2020, and proposes a strengthening method based on Fabric Reinforced Concrete Mixture. Through finite element analysis, it is concluded that concrete minarets can be strengthened safely from the inner surface with the Steel Fabric Reinforced Concrete Mixture method.