Browsing by Author "Aras, Fuat."

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    Earthquake protection of Beylerbeyi Palace by reversible mixed technologies
    (Thesis (Ph.D.)-Bogazici University. Institute for Graduate Studies in Science and Engineering, 2007., 2007.) Aras, Fuat.; Aşkar Altay, Gülay.
    The historical building stock and seismic risk of Anatolia draws considerable attention of the engineers for studying the earthquake performance of these structures and investigating appropriate protection techniques. In this respect, this study aims to examine the earthquake performance of the historic Beylerbeyi Palace which is a representative of the great buildings in the late of 19th century in Istanbul and elsewhere in the Ottoman Empire and search the possible retrofit techniques by means of reversible mixed technologies within the framework of FP6-Earthquake Protection of Historical Structures by Reversible Mixed Technologies (PROHITECH). Starting with the mineralogical structure of the mortar and ending with mechanical properties of masonry, material identification process has been carried out. Later on Ambient Vibration Survey, (AVS) was conducted in the structure with the University of "St. Cyril and Methodius", Institute of Earthquake Engineering and Engineering Seismology. Numerical model of the palace has been constructed and calibrated according to results of AVS. Response spectrum analyses have been carried out by using three different earthquake cases, defined by accounting the site specific soil and seismic characteristics of the site. The performance of the structure was assessed as weak. Furthermore the vulnerable parts of the structure were revealed by nonlinear analyses. Finally according to results of the analyses and considering the historical and architectural perspective of Beylerbeyi Palace three different retrofit strategies have been proposed and discussed in details. According to order of presentation, the first proposed strategy is the use of fiber reinforced polymers. The second strategy is the installation of the base isolation and the last one is the consolidation of the roof level to have the rigid diaphragm behavior with the application of fiber reinforced polymers to the required walls.
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    The effects of partition walls on dynamic behavior of RC buildings
    (Thesis (M.S.) - Bogazici University. Institute for Graduate Studies in Science and Engineering, 2019., 2019.) Koç, Erdem.; Soyöz, Serdar.; Aras, Fuat.
    Reinforced concrete buildings constitute a signi cant part of the building stock of Turkey, and the investigation of their structural behavior is essential. This study aims to concentrate on the inclusion of in ll walls into the numerical model of the studied building. For this reason, an existing six-story reinforced concrete building is considered as a reference structure to assess di erent modeling approaches de ned for in ll walls, such as shell and strut models. Dynamic properties of structures are inherent properties which depend on their mass and rigidity. Therefore these properties contain vital parameters for the assessment of structural behavior. In this study dominant frequencies and mode shapes of the building are determined by Ambient Vibration Testing. Acceleration records gathered from each story level are analyzed in the frequency domain with Peak Picking method. Modulus of elasticity, unit weight, compressive strength, and shear strength are determined by testing the wall specimens extracted from the existing building according to European Norms. Thereby the required data for the construction of a numerical model is completed. Numerical models for the studied building are constructed with nite element method by using di erent modeling techniques for in ll walls. In the rst model, the rigidity of in ll walls is ignored as it is done in state-of-the practice. The second model is constructed by idealizing the in ll walls by shell element. The results of these two models showed that partition walls signi cantly a ect the dynamic behavior of the structures. Finally, two strut models are constructed separately as one directional single diagonal strut and two directional single diagonal struts for each in ll walls. Eigen Value analyses performed for each model to analytically determine the modal parameters. Comparison of experimental and numerical results indicated the accuracy of modeling technique.