The effect of boundary conditions in two dimensional dynamic soil behavior analysis

In this dissertation, the effect of boundary conditions on ground response analysis is examined with different geometries by means of one and two dimension dynamic analysis. Flac 2D software for two dimension and Deepsoil software for one dimension were used in the analysis. One and two dimensional analysis results showed that the horizontal layers infinite extension gives similar and close results. Two-dimensional output accelerations and one-dimensional analysis results were compared for models representing different valley geometries and differences were observed. In two dimensional analysis, valley width and slope angles of valley side surfaces were considered as variables in geometry boundaries. In addition to geometry, soil material model and acceleration input were defined as variables in the analysis. In the models created for the geometries where the slope of the base rock increased and the valley width decreased, the output surface accelerations were diverged to accelerations obtained in one dimension. It was observed that the soil types and base rock geometry has an effect on the results while performing the soil dynamic analyzes at a designated site. The amplifications for the edge of valleys (for wide valleys) and at the middle of valleys (for narrow valleys) in two-dimensional analyses are quite high when compared with one-dimensional analysis amplifications.