Under seismic loads, soil-structure interaction, and its effect on performance of pavements is more important today. Turkey is located in one of the most active seismic zones in the world. In the past, many destructive earthquakes happened in Turkey. The fact is that due to frequent earthquakes in the future, we may suffer a significant loss of life and property. Therefore, it has been necessary to minimize demolitions by conducting soil behavior analysis for each site. To design buildings, bridges, and other structures with base-isolators according to performance, it is necessary to carefully evaluate the long-term ground motions, especially in determining the earthquake ground motion. In these evaluations, empirical and theoretical methods to predict the response spectrum, considering and analyzing the effects of the near-fault, scaling the spectrum for different damping ratios, and simulation of long-term ground motions time-history constitute an essential place. It is necessary to determine the principles required for modifying the design spectrum in the long-period boundaries. The regulations are required to simulate long-period ground motions in the time-history and the necessary rules for selecting and scaling the earthquake ground motion records by considering the long-period effect. In this thesis, commonly used approaches in national and international regulations in defining the earthquake effect were evaluated, and the recommended earthquake levels for structures within the Düzce city in Turkey are explained. While evaluating the earthquake hazard in the study area, the general geology, tectonic features, ground conditions, and existing fault systems of the region were considered. For the study area, besides the classical hazard spectra, hazard curves for different spectral ordinates that allow the calculation of probabilistic seismic hazard maps and spectral coordinates for various periods are presented. Earthquake records were selected according to these spectra, and nonlinear analyses were made by simulating earthquake data for structural analysis. Turkey Earthquake Building Regulations (TBDY, 2018) to determine the seismic design spectrum is considered.