2D seismic response of the Duzce Basin, Turkey

Abstract

The existence of the inclined bedrock at the basin edges bring about the concentration of the damages at these areas. The graben-like Duzce Basin with a low inclined subsurface topography is prone to exhibit such effects. In this study, at the first, Duzce Basin edge model is extracted from the data obtained from performed microtremor surveys as well as geotechnical investigations. Using these data, the basin stratification and shear wave velocity profile as well as the geotechnical properties of the layers is identified. Based on these data, the idealized Duzce Basin edge model is proposed. Then, to estimate the dynamic behavior of the Duzce Basin, a fully nonlinear method based on explicit finite difference scheme is performed. The basin is subjected to the collection of 16 strong ground motions with different peak ground accelerations (PGA) levels. Using the recorded acceleration at 12 surface points along the basin edge the variation of the maximum spectral amplification factor is reported. The results show that the Duzce Basin edge behavior is greatly affected by inclined bedrock. Also, the sensitivity of the different points of the basin to different periods is investigated. It is seen that in the case of the motions with the PGA of 0.2g, this band spans between 0.1s to about 1.7s.