Ground response analysis of Bahlui Clay as a foundation layer

Abstract

The purpose is to evaluate ground response of 30 m soil column subjected to different seismic actions. The main foundation layer under investigation is a fat clay specific for Iasi, the Bahlui clay. Three main investigation steps have been followed. The first one consists in laboratory tests using resonant column and torsional shear tests only for Bahlui clay. Degradation curve has been established for both shear modulus and damping ratio. Dynamic parameters of the other layers have been established using empirical models. The second step consists of determination of the site's response spectrum. Equivalent linear one‐dimension analysis using STRATA software has been performed in order to determine the seismic response of the soil column. The analysis results highlight an amplified seismic input motion associated with each soil layer type. They will lead to a better understanding and will improve the characterization of the site response effects, necessary for the local engineers to manage the design of new constructions and to properly consolidate the existing ones.