Vienna Congress on Recent Advances in Earthquake Engineering and Structural Dynamics 2013 (VEESD 2013) C. Adam, R. Heuer, W. Lenhardt & C. Schranz (eds) 28-30 August 2013, Vienna, Austria Paper No. 475 Abstract. Hagia Sophia is one of the most well known monuments in the history of architecture. It is a very innovative structure within its construction period both from architectural and engineering standpoints. The construction of the masonry structure was completed in the 6th century. Besides the reconstruction of the dome, which collapsed only 20 years after completion of the monument, the structure survived more than 1500 years with only secondary damages and partial collapses. Due to this outstanding performance against numerous earthquakes in its long history, it is important to provide engineering information in order to understand the structure itself as well as its vulnerabilities, which might be regarded as initial steps to develop efficient proposals if required. The paper presents the preliminary results of the research carried out with the support of HPS-Europa2 Transnational Access Programme. In order to accomplish the engineering tasks, FE modelling with high performance computing was used during the research. Large and detailed FE models were received from the Institute of Mechanics at the KIT Karlsruhe to represent the structural system. Within the framework of this paper, a series of analyses concerning the primary and secondary structure will be presented. Keywords: Hagia Sophia; Earthquake behaviour; Numerical analysis 1 INTRODUCTION The church of Hagia Sophia in Constantinople was built in 6th century during the reign of Justinian. The construction lasted in a fairly short time in comparison with its huge scale, only five years and ten months between 532 and 537 (Procopius 2006). The architects Anthemius of Tralles and Isidorus of Miletus established a unique structure, by means of combining architectural and structural innovative arrangements, which astonishes in the very first sight even today(ibid). However, due to the high seismicity of the Marmara region, Hagia Sophia has suffered from numerous earthquakes during its long history. In 558, only 20 years after completion of the church, the central dome, including its supporting elements, partially collapsed due to an earthquake in 557. Nephew of Isidorus was assigned for the repair works and a new dome with an altered form was completed in 563 (Müller-Wiener 2007). However, this second dome of young Isidorus was also damaged and partially rebuilt on two occasions (Van Nice 1963). First, the western part of central dome with its adjacent parts including the western arch and semidome collapsed in 989. Second in 1346, the eastern part of central dome and the adjacent main arch and semidome partially collapsed (Mainstone 2006). During Byzantine and Ottoman eras, there had been some later additions to the original texture, which altered the exterior appearance of the church. Those additions included structural elements such as buttresses in order to avoid further damages from the earthquakes. Structural behaviour of Hagia Sophia under dynamic loads U. Almac 1 , K. Schweizerhof 2 , G. Blankenhorn 3 , C. Duppel 4 , F. Wenzel 5 1 Faculty of Architecture, Istanbul Technical University, Istanbul, Turkey 2 Institute for Mechanics, Karlsruhe Institute of Technology, Karlsruhe, Germany 3 Livermore Software Technology Corp., Livermore, CA, USA 4 B+G Ingenieure Bollinger und Grohmann GmbH, Frankfurt am Main, Germany 5 Karlsruhe Institute of Technology, Karlsruhe, Germany