AYASOFYA YERALTI YAPILARININ ÜÇ BOYUTLU GÖRÜNTÜLENMESİ VE BELGELENMESİ (original) (raw)

2020, PROCEEDINGS OF THE INTERNATIONAL HAGIA SOPHIA SYMPOSIUM

The Three Dimensional Scanning and Visualisation of the Underground Structures of Hagia Sophia The Hagia Sophia, built in the Late Antiquity, has reached the present day with minor repairs as much as possible, with the concern of giving further damage to its structural integrity. Only the repairs after earthquake damages were extensive interventions such as the buttresses added to the main building that are exceptions of this condition during its long lifetime over centuries. Hagia Sophia has been depicted in European painting techniques by European travelers with perspective and plan drawings since the 15th century. Nevertheless, visual data for its underground structures is notably new. Throughout the 20th century, scholars have carried out many surveys for the superstructure that was in priority. Yet, so far, no systematic and holistic architectural documentation has been carried out for the underground structures of the building. As a result of not conducting such a study, air conditioning problems related to the infrastructure of Hagia Sophia continued until today, and the perception of the building as a whole with all its related substructures was not possible. No matter how comprehensive the surveys on the existing superstructure carried out with modern imaging devices are, it is comprehensible that all repair, rehabilitation, and ventilation works will be incomplete and inadequate without establishing the relationship of Hagia Sophia with its underground structures. The research for the substructures of Hagia Sophia carried out by BUMAK in 2009 and Çiğdem Özkan Aygün’s team in 2010, revealed that they required thorough architectural documentation. This study aims to understand and document the underground structures of Hagia Sophia that are the ventilation canals, tombs, and wells. Yet another objective is to examine their possible relations with the Second Hagia Sophia (408-532 CE). Investigating the substructures, which are supposed to serve as ventilation, groundwater control, rainwater discharge, and water installation canals can contribute to understanding the causes of the current humidity problem of Hagia Sophia. Within the scope of this study, we have scanned the above-mentioned spatial units with three-dimensional laser scanner devices. A diagnostic for the continuity of the underground structures was possible with the help of a partial Ground Penetrating Radar implementation. Underground corridors that should have structural continuity, but do not allow access due to silted debris and mud piles were the subject of this study on the ground floor level. Prior to the scanning work, a determination for the methodology of this research was necessary. Therefore, we visited the building in January-February to define the methods and devices. After our examinations, we concluded that the corridor under the inner narthex was appropriate to scan with the Faro Focus 150 S laser scanning device since this corridor is relatively higher than the other underground structures. The processing of the obtained data would be possible with Faro Scene software. For the rest of the underground corridors, which are narrower and lower in elevation, Faro Focus 150 S was not suitable for use due to its weight and dimensions. Thus, it would be possible to obtain digital data and photographic data with the Leica BLK360 Camera Laser Scanner, which was easier to carry and use in low and narrow spatial units. For the water-filled wells, our method was to create a point cloud from underwater photographs taken by the help of expert divers and combining with the clouds of previous scans. Finally, the conclusion of the preliminary research showed us the necessity for the combined use of these three methods to visualize the substructures of Hagia Sophia. For the continuation of our research, after Fatih Sultan Mehmet Vakıf University got the permission from the General Directorate of Cultural Heritage and Museums, the field studies of the Hagia Sophia underground structures scanning project, which we carried out in cooperation with the Hagia Sophia Museum Directorate, was run between 29 June-16 July 2020. Assoc. Prof. Hasan Fırat Diker, Assoc. Prof. Mine Esmer and Dr. Alidost Ertuğrul from Faculty of Architecture and Design at Fatih Sultan Mehmet Vakıf University and Lecturer Hakan Eğilmez from the Department of Fine Arts at Istanbul Technical University conducted the research project. It was possible to scan and visualize the underground structures and wells of Hagia Sophia, which has a total length of approximately 900 meters through this study carried out under difficult circumstances. The aim was to examine thoroughly the infrastructure that provides the air circulation under the ground flooring of Hagia Sophia. Thus it would be possible to develop suggestions for the removal of the debris and mud which has silted and which prevents air circulation in some parts of the channels. This three-dimensional scanning and documentation study targets to understand the architectural features and functions of the Hagia Sophia underground structures. The research by uncovering the infrastructure problems indicates the need for further qualified and in-depth surveys on Hagia Sophia. The outputs of our research aim to contribute to infrastructural repair works in the near and long –term projects. Decades, perhaps centuries of neglect of these underground structures, which we have identified with our study, may be useful to eliminate existing air conditioning and humidity problems. It is understandable that silting, collapses, and thrash in the underground system will cause visible structural problems above the ground. A thorough study is necessary to eliminate the troubles detected in our survey. We completed the research just before the conversion of the building to serve as a mosque. In this period of change in the status of the building, we could finish our work with the support provided by Hayrullah Cengiz, the last director of the Hagia Sophia Museum. We hope that the three-dimensional documentation we have carried out to enhance the protection of the building and eliminate its problems will contribute to the preservation of this world heritage monument after the change of function it has undergone.