Performance assessment of a new building designated according to Turkish earthquake code by nonlinear elastic methods

Our country is located in the earthquake zone. Many earthquakes have been experienced in the past, and it is an inevitable fact that these earthquakes can be experienced again. As a result of the earthquakes that occurred, deficiencies of structures against earthquake performance were revealed. In order to minimize the loss of life and property in earthquakes, the examination of the behavior of earthquake-affected buildings of existing buildings and new buildings has gained a special importance. In the light of these developments, the concept of performance was included in Turkish Earthquake Code 2007. With the ongoing Urban Transformation Projects in Istanbul province, risky buildings that are not suitable for regulation are destroyed and new buildings are being constructed in compliance with Turkish Earthquake Code 2007. In new buildings built with urban transformation projects, toothed floor and flat beams are generally preferred. Deep beams are used on the blind façades. In this thesis study, an 8 story reinforced concrete building was designed to examine the earthquake performance of the buildings built within the scope of Urban Transformation Projects. In order to be similar to the buildings built in the urban transformation projects, Toothed floor was chosen as floor type and flat beams, beam with limited heights, were used. The building is designed symmetrically with respect to the X and Y axes to prevent torsional irregularity. The building is 29 meters in the X direction and 17 meters in the Y direction. The floor heights are 3 meters and the building height is 24 meters. The building is in the first earthquake zone and soil class is Z2. STA4CAD is one of the most commonly used static calculators in our country. In this study the building was designed with the help of the STA4CAD. It is designed according to Turkish Earthquake Code 2007. Turkish Earthquake Code 2007 includes three types of nonlinear analyses. According to Turkish Earthquake Code 2007, building performance level is determined by using incremental equivalent seismic load method and time history analyses by nonlinear elastic evaluation methods. Performance analysis was done with SAP2000 and STA4CAD calculation programs. Before the nonlinear analyzes are applied, in order to describe the nonlinear behavior, plastic joint assignment is made. It is defined only at the lower ends of the shear walls while being defined at the two ends of the columns and the beams. In the STA4CAD program, pushover analysis, one of the linear nonelastic evaluation methods, has been applied. With SAP2000 program, performance analysis was performed by using pushover analyz and dynamic time history analyz by using nonlinear evaluation methods. An static pushover analysis was applied to obtain the peak displacement-base shear force curves, also called the structural capacity curves of the structure. Pushover analysis is a step-by-step pushing process, keeping the ratio between the levels of the structure constant. In order to find the performance point, the building's demand curve intersected the capacity curve with the spectrum curve for the earthquake with a probability of 10% surge in the design earthquake of 50 years. Before this operation, the coordinate transformation is performed for the two curves. The dynamic time history analysis is more based on acceptance than pushover analysis. The time history analyses is based on the nonlinear behavior of the system and the equation of motion of the system under an accepted earthquake motion is numerically solved. For dynamic time history analysis, 7 earthquake records were scaled according to Turkish Earthquake Code 2007 . For time history analysis, the performance evaluation was carried out by taking the average of the results obtained when the X and Y directions of each earthquake record were influenced by the structure. The total curvature-normal force graph was drawn with the XTRACT program using the damage limits according to Turkish Earthquake Code 2007 for each column type to determine the damage level of the columns. The normal force-total curvature from XTRACT shows the damage level by showing the values of nonlinear behavior on the graph. Damage levels of shear walls and beams were obtained with SAP2000. The results found by different methods and programs were compared based on element and system. Then all the results discussed.