The damping of saturated poroelastic soils during steady-state vibrations

Herein, we analyze the damping that arises from the soil-water interaction within nearly-saturated soils during steady-state vibrations. Based on the two-phase theory of Biot, we analytically derive the spectral response of a column made of nearly saturated poroelastic soils as a function of soil stiffness, degree of saturation, porosity, specific gravity, and permeability. A parametric study determines the influence of these parameters on the fundamental period, maximum amplitude, energy dissipation, damping factor, and maximum pore pressure. In departure from common beliefs in soil dynamics, we conclude that the soil-water damping within fully-saturated sands is not negligible compared to structural hysteretic damping.