Theoretical investigation of the behavior of high-rise steel tubular systems

Due to the insufficiency of regulations and technical information on the design and performance evaluation of high-rise buildings under vertical and horizontal load effects until recently, and the fact that the existing information is mainly about reinforced concrete buildings, engineers in our country have directed the design and construction of reinforced concrete high-rise buildings. In the 2007 Regulation on Buildings to be Built in Earthquake Zones, there is no section on high-rise buildings and these buildings are excluded from the scope of the regulation. It is seen that this situation has remained as a deficiency for years for the relevant engineers and academicians both in theory and practice. With the 2018 Turkey Building Earthquake Regulation (TBDY 2018), the design of high-rise buildings has been evaluated under a separate heading for the first time. Before this date, it is seen that the Istanbul High-Rise Buildings Earthquake Regulation, which was prepared by the Istanbul Metropolitan Municipality to Boğaziçi University, Kandilli Observatory and Earthquake Research Institute, was used for high-rise buildings in Turkey. The design philosophy in this regulation is similar to the principles in Chapter 13 of TBDY 2018. In this thesis, firstly, the design and development processes of high-rise buildings are examined, the design philosophy of high-rise buildings is examined and brief information about the structural systems used in such buildings is presented. The focus is on analyzing the earthquake performance of high-rise buildings with steel structures in general and composite tube systems in particular in accordance with the provisions of TBDY 2018 Chapter 13. In the study, the behavior of different composite tubular systems with different seismic design classes under earthquake effects is analyzed. The analyses are carried out on buildings with composite diagonal and frame tubular systems consisting of 72 floors in Mersin and Hatay provinces with different seismicity classes. While pursuing this objective, many relevant sections of the Turkish Building Earthquake Code (TBDY 2018) and the Principles of Design, Calculation and Construction of Steel Structures (ÇYTHYE-2018) regulations have been mentioned due to the wide scope of the subject. For this reason, TBDY 2018 evaluated the design of these high-rise buildings in a separate specialization class. For this purpose, it is aimed to contribute to this field with this study on composite tall buildings based on the determination that the studies on tall buildings in our country are limited and the studies on this subject are mainly on reinforced concrete tall buildings. The earthquake performances of different composite tubular systems (braced and frame tubular systems) were analyzed in locations such as Mersin and Hatay with different seismicity classes. As a result of these comparisons, the advantages and disadvantages of different tubular systems are presented. The theoretical behavior of the systems under earthquake loads is investigated and their structural performances are evaluated. This study concludes that in places with high seismicity and high DTS such as Hatay, crossed composite tubular systems should be preferred and in places with low seismicity such as Mersin, frame tubular systems should be preferred. And with this study, it is thought that it will contribute to the understanding of the earthquake performance of high-rise buildings and to understand the design philosophies of tubular systems within the scope of TBDY 2018. Analyzes for different earthquake scenarios and locations are predicted to provide practical information that can be used in engineering applications. As a result of the study, it is thought that detailed information and evaluations on different earthquake design classes and earthquake performances of tubular systems will provide preliminary ideas to experts and scientists working on the subject in practice and theory.