There are many Ottoman minarets with different architectural and structural features in Anatolia. But, examples of minarets with covered balcony are very rare. Therefore, in order to protect these minarets against possible earthquakes, it is necessary to investigate the structural properties and determine the dynamic characteristics before performing seismic analysis. In the scope of this paper, the dynamic characteristics of the covered balcony minaret of Green Mosque, which is located in Kütahya were examined. The study includes general information about the structural characteristics of the minaret and the dynamic behavior changes between the cases, which the minaret has open or covered balcony. The determination of the dynamic characteristics of historical minarets is troublesome. Because, the historical masonry minarets have complex stiffness, high heterogeneity and shadowy boundary conditions as observed. Thus, ambient vibration test was performed with aim of defining modal parameters of the minaret. The test was applied using two different types of accelerometers and the results were compared with each other. Since the dynamic behavior of the minaret were also represented with numerical model, solid model were implemented by using the finite element technique. Model updating was performed in order to match the natural frequencies arising from the experimental investigation with those from numerical results. Then, the minaret was modeled as open balcony with the same material properties and geometric dimensions and modal analysis was performed on this new model. The mode shapes and modal frequencies obtained from both models are compared with each other. Whereby, the effect of covered and open balcony to the dynamic behavior of the minaret was interpreted. Furthermore, considering elastic acceleration spectra, calculated horizontal load of the minarets were compared with each other according to the first and second modes.
Keywords: Historical minaret, Balcony type, Dynamic behavior, Ambient vibration test, Modal analysis, Horizontal force