Comparison of earthquake performances of different composite column structures with linear and nonlinear analysis methods

Keywords: Reinforced concrete structure, Steel structure, Composite structure, Concrete filled steel tube section, Concrete encased steel section, Partially concrete encased section, Response spectrum analysis method, Pushover analysis method. Composite structures have gained wide acceptance worldwide because it combines the positive properties of both Steel and concrete. In this thesis, 7 different model buildings with the same design, divided into 3 groups, were analyzed in order to determine the earthquake behavior of different composite structures. The structures in each group were compared with each other according to the results of the analysis. This study was carried out in accordance with the regulations of TBDY-2018 and ÇYTHYE-2016. ETABS V19.1 computer program was used for the analysis. Response spectrum method was used for the linear earthquake calculation, while the pushover analysis method was used for the non-linear analysis. In these structures, C30 concrete, B420C rebar bars, and S275 steel were used. The structures were chosen as workplace, soil class ZB and Earthquake ground motion level DD-2. In the first Group of building models, two structures were used, the first structure is an RCC structure, while the second structure is a composite structure, the difference between these two structures is that the columns of the second one are encased steel composite columns. In the second Group of building models, three different composite structures were used, the elements of these structures except the columns have similar properties, composite beams were used while in the columns three different composite columns were used. Concrete encased steel sections, unreinforced, and reinforced concrete-filled steel tube composite sections are used in the columns. İn the third Group of building models; steel structure and partially concrete encased steel composite structure were used. Composite beams were used in both structures, just the columns are made from different sections. Generally, better seismic performance was observed for composite structures compared to reinforced concrete and steel structures.