Parametric study of the seismic ground response of a linear visco-elastic soil layer improved by stone columns or pile-like elements

This paper presents a qualitative investigation on how soil improvement influences ground response during earthquake events. The paper focuses on how modifications to stiffness, damping ratio and unit weight of soil reflect on the amplification functions. The study is carried out by means of finite element analyses using a linear visco-elastic material model and rigid bedrock conditions. The accelerogram recorded during the 1989 Loma Prieta (USA) earthquake is used as bedrock input motion. The results of this study suggest that under certain conditions the seismic load on the structures could be increased or decreased by changes of the eigenfrequencies and amplification functions of the natural ground conditions due to soil improvement.