Investigation of dimension effect on the soil amplification

Seismic waves emanating from an earthquake source propagate through layers of soil at varying speeds until they reach the surface, generating vibrations upon arrival. The intensity and duration of these vibrations depend on factors such as the magnitude of the earthquake, distance from the source, and characteristics of the soil and bedrock. Soil layers can exhibit properties that either amplify or dampen seismic waves. The focus of this study, soil amplification, refers to the phenomenon where seismic wave amplitudes increase as they pass through soil layers, influenced by the physical and dynamic properties of these layers. Loose and soft soil layers, for instance, can amplify seismic energy, resulting in larger surface vibrations. In this thesis, 11 earthquake acceleration records reflecting the seismicity characteristics of the research area were scaled and analyzed using the DeepSoil program for one-dimensional nonlinear soil amplification analyses. Two-dimensional analyses were conducted using Plaxis 2D, while three-dimensional analyses employed Plaxis 3D to evaluate soil responses. Recommended methods for different dimensions were applied comparatively. The study aims to establish a relationship between various dimensions based on the analyses conducted. The results of lengthy three-dimensional analyses were compared with those of shorter-duration two-dimensional and one-dimensional analyses to streamline analyses times. Despite numerous studies in the literature on dimension effects, effective alternative methods for the dimensions used in these studies have not been proposed. This study aims to investigate dimension effects to achieve accurate results and enhance their applicability in engineering practice.