Examination of structures built with tunnel formwork in terms of strength and cost according to the Earthquake Regulations of 2007 and 2018

Turkey has always been exposed to active fault lines passing through and unpredictable seismic activities. These ground movements have always been one of the important issues in our country, which have led to great destruction and loss of lives and property in its past. For this reason, our earthquake codes, which aim to design more accurately against earthquake movements, are continuously made improvements. In this research, the analysis of structures built with tunnel formwork system which is popular today with the new earthquake code entered into force in 2019, the strength and cost according to the old earthquake code in terms of what differences will occur. In addition to the research, investigated how the number of storeys and regular floor plans affect the results. For this purpose, two types of structures were covered with 5, 10, 15, 20, 25 and 30 story models were created, first in the 2007 earthquake code, then in the 2018 earthquake code, design analysis was carried out. As a result, the new earthquake code, which came into force in 2019, led to more realistic results as it provides more accurate environmental inputs used in design analysis. Horizontal earthquake loads affecting floors increased by 2,1% for 5 story in regular structures, decreased by 21,8% for 10 story and 12,2% for 15 story. In more irregular structures, it increased 18,8% for 5 story, 10 story structure decreased by 11,4% and 15-storeys structure decreased by 10,5%. In terms of cost, there was a 0,07% increase in total cost in 5-storey buildings, 2,45% in 10-storey buildings and 3,91% reduction in 15-storey buildings. Additionally, an empirical formula was derived to estimate the cost per square meter based on the number of stories.