Investigation of the suitability of steel pedestrian overpasses produced with different methods to ÇYTHYE-2018; the sample of Ankara city

In the steel structure design, taking into account the calculations specified in the ÇYTHYE-2018 regulation and the TS-648 standard, overpasses made of steel and made before 2018 were investigated. In the study, design principles, load combinations, vertical displacements were examined within the scope of TBDY-2018 and DBYBHY-2007 earthquake regulations and the weaknesses and strengths of standards and regulations were emphasized. Within the scope of this thesis, three different types of steel pedestrian overpass projects, namely middle pedestal, arched and pylon, whose static project was approved and manufactured according to the old standards / regulations by Ankara Metropolitan Municipality were examined. Both the condition of the steel overpasses in the year they were built and their status in the new regulation (ÇYTHYE-2018) were investigated. In the analysis, SAP2000 program, one of the structural analysis programs widely used in civil engineering, was used. In the thesis study, the internal forces, capacity ratios and vertical displacement values of the overpasses were compared with the regulations / standards of the year they were manufactured and solution proposals were prepared according to the current regulations. In addition, sections were arranged according to the cross-section conditions and capacity ratio limits of the systems and tonnage calculation was made. As a result, according to the analysis made with the current standards / regulations, it was determined that the internal forces of all three systems increased and their capacity rates decreased. In the calculation made according to the first 6 element groups where the highest internal forces occur in the systems, the capacity utilization rate has decreased by 28% on average. There has been an average decrease of 20% in the tonnages of the systems where new sections are assigned. Current standards/regulations enable for more economical design of steel overpasses, which are mostly made for the public benefit. At the same time, with these advantages of the new steel structures regulation, it is seen that the steel structures will play a role in the preference of more than before.