Nonlinear dynamic behavior of the basins with 2D bedrock

Abstract

Resonance due to impedance contrast, focusing due to subsurface topography, conversion of the body waves to surface waves and subsurface topography are among the factors influencing the amplification specification of the sites, which can only be considered by the application of suitable nonlinear analysis method. In this study, using the fully nonlinear analysis method, along with a hysteretic-type model and no extra damping, the effects of the basin edge on the dynamic behavior of the basins is investigated in more accurate manner. To make the results useful at engineering affaires, the investigated basins are classified into sandy, clayey and layered basins. Special degradation curves for each of the (soft, medium plasticity and stiff) clay and (loose, medium dense and dense) sand types have been extracted and fitted to the continuous functions which is used by the nonlinear method's hysteretic-type damping scheme. The results exhibit the differences in the amplification behavior of the basins with different soil types under the different excitation levels. Also, the sensitivity of the different parts of the basin surface with 2D geometry to different period levels is investigated. This finding can be used at dynamic structural design of the buildings on basins with 2D bedrock inclination.