Identification of Subsurface Structures and Dynamic Modulus Determination Based on Downhole Seismic Surveys (Case Study)

Abstract

Seismic features of the site are studied in earthquake prone areas. In these studies, the seismic design parameters of the site are determined based on geological and geotechnical engineering features. In this regard, part of the building regulations (European Standard) is related to site classification. In order to classify the land, the bylaws provide various methods such as mean shear wave velocity up to 30 m depth. In the present study, the values of the dynamic modulus of layers are calculated using conventional relationships based on the values of wave velocities for different depths. In this study, data from 22 boreholes, in which Downhole Seismic surveys were performed, were identified and implemented to identify subsurface layers and to determine the dynamic modulus in the area. The results of these studies in land classification were used to evaluate the site effect based on European Standard. The results show that the area under study is classified in class B according to this standard.