Amplification of seismic wave motions in partially fluid-filled poroviscoelastic media

Abstract

This paper presents a simple and an efficient formulation of wave motions in partially saturated poroviscoelastic soil media. The viscoelastic property of the solid skeleton is incorporated into the elastic moduli via a simple relationship between the skeleton damping and the relaxation time established based on the Kelvin-Voigt model. The proposed formulation is adaptable to various soil configurations. It has been successfully applied to some vibrational problems of nearly-saturated soil columns made of different materials and carrying different loadings. The consideration of the skeleton damping, which does not receive a sufficient attention in previous works unlike the Biot flow - induced damping, significantly reduced the motion amplification amplitudes as well as the accelerations and Fourier spectra amplitudes at the surface of actual sites. As a useful application of the present formulation, the motions obtained at the ground surface of actual sites have been applied as inputs to a wind turbine to obtain its response in the time domain. The maximal relative displacements of the turbine were substantially reduced due to the skeleton damping. The vertical response of the turbine still negligible compared to the horizontal response.