Effect of beam-column connection rigidities and soil-structure interaction on seismic performance of steel frames

As it is known, structures are exposed to non-linear deformations under the influence of earthquakes. However, the design methods given in the regulations are generally based on the assumption that the structures are linear elastic. The nonlinear behavior is reflected in the solution by using some coefficients. Therefore, inelastic behavior is taken into account with a certain approach. On the other hand, displacement-based seismic design of structures takes inelastic behavior into account more accurately. In this approach, the target drift value in the design eartquake is determined at the beginning of the design. Thus, a structure can be designed to have the desired performance. In addition, the cost of the damages under earthquakes in structures designed with displacement-based approach can be reduced by estimating. In this study, seismic performances of 2D steel frames with various column-beam connection rigidities were evaluated using pushover analysis method. In the first chapter, a brief information about ATC-40, FEMA 356 and TBDY 2018 regulations and structure-soil interaction models are given. In the second part, base shear forces, horizontal displacements, demand curves, capacity curves, performance points and plastic deformations obtained on the buildings with 4, 6 and 8 floors are presented. In addition, the same buildings were analysed considering soil-structure interaction and the results were compared with the results obtained from the models without subsoil. The soilstructure interaction was taken into account using Pasternak subsoil model. It was concluded that beam-column connection stiffnesses and soil conditions significantly affect the seismic performance of the structure.