Investigation of earthquake behavior of masonry structures using ambient vibration test: Adana Great Clock Tower example

Historical structures are buildings that have cultural heritage characteristics and should be protected. Many assumptions are made in the finite element modeling of historical buildings, whose structural behavior depend on many variables. However, these assumptions often do not reflect the real behavior of the building. In order to determine the earthquake behavior of these structures accurately, it is important to update and use finite element models based on experimental data. In this study, Adana Great Clock Tower, which is a historical masonry structure, was chosen as an application example. For this structure, firstly, initial finite element model was created, and then natural frequencies and modes forms of this model were determined by using the modal analysis method. Next, experimental measurements of this structure were made by using the Operational Modal Analysis method, and natural frequencies and modes forms of the current situation were determined. The initial finite element model of the structure was updated depending on these experimental frequencies and modes. The nonlinear material parameters of the updated finite element model were determined to reflect the nonlinear behavior, and static pushover and time domain earthquake analyses of this model were performed. Four different earthquakes were selected to be used in time domain earthquake analyses, two horizontal components of each earthquake were scaled according to DD2* 1.3 and DD3* 1.3 earthquake level design spectra defined in TBDY-2018 and applied to the structure. Two horizontal components of the same earthquake were applied once again to the structure by rotating 90°. As response quantities, the time variations of the peak displacement and base shear force, the variation of lateral displacement along the height before failure of structure, and the plastic deformation formed due to damage were evaluated. The effectiveness of different earthquake records and application directions on the results has been assessed.