Photogrammetry in Documentation and Ambient Vibration Test of Historical Masonry Minarets

Abstract

This study was conducted to investigate modal parameters (e.g. mode shapes and modal frequencies) of a masonry-type historical minaret by performing numerical and experimental analyses. The Operational Modal Analysis technique was used for the experimental study to obtain modal parameters of a historical masonry minaret. For this purpose, the Buyuk Mosque located in Samsun, Turkey, was chosen for the experimental analysis. The photogrammetry method was used to document the minaret and to create a finite element (FE) model. The Frequency Domain Decomposition (FDD) method was utilised to experimentally identify the natural frequencies and mode shapes. ANSYS software was used to carry out 3D FE modelling of the historical masonry minaret and to analytically determine the natural frequencies and mode shapes of the minaret. Furthermore, the FE model of the minaret was calibrated according to the experimental results using the Response Surfacebased FE model calibration technique to obtain more accurate results of the modal parameters of the structure. The results of the experimental, initial, and calibrated FE model were compared. Significant differences were noted when comparing the results of the experimental and analytical studies to the initial conditions. Model calibration techniques are necessary to obtain a more reasonable FE model.