Geometric Evaluation of Hagia Sophia

Hagia Sophia is one of the most prominent architectural and structural creations in the history of mankind. Since it has been standing for the last 15 centuries, it is noteworthy to be worked on. Hagia Sophia is known to be located on eartquake zone and has high level of deformation since it has been constucted. Therefore, learning its mystery requires a great variety of analysis. Besides, instead of studying on the ideal geometry of the structure, it would be more enlightening to reveal the real deformed shape of it. An important point to be considered is using non-destructive techniques. Hence, 3D laser scanning is an effective method for this purpose. This study aimed to observe the designed and the deformed geometry of Hagia Sophia. First the structure is scanned by 3D laser scanner from both inside and outside. The point clouds obtained by each scan are combined by Cyclone software. This part of the study covers the process after the combined point cloud is meshed on 3D Reshaper software. The software allows the user to measure every detail, moreover creating ideal geometric shapes for each element is possible. In this study, the structure is first observed in detail of each structural element, then as a whole. It is seperated as primary and secondary system. In the title of primary system, first the main piers are examined, then the main arches, the main dome and dome base, tympana and the pendentives. The secondary system covered the secondary piers, secondary domes, exadrae domes, barrel vaults and the buttress piers. According to the element, the ideal geometric shapes are created like ideal vertical planes for the piers, ideal cylinders for the arches, ideal sphere for the dome etc… The comparison of the ideal geometry and the real one points the deformation. Hence, the study reveals the deformation that Hagia Sophia has undergone during the centuries.  Besides, when the ideal geometric shapes are considered as a whole, they form a consistent design. Once the shapes created seperately joined together,  they agree in the center of the structure, which supplies a satisfying verification about the study. Therefore it might give a clue about the designed geometry of Hagia Sophia. Consequently, this study will improve the structural analysis of Hagia Sophia based on more realistic data in terms of geometry.