Impedances for Radially Inhomogeneous Viscoelastic Soil Media

Abstract

The dynamic impedances of a radially inhomogeneous viscoelastic soil layer with a ~entra~ h?le are formulated based on a new boundary zone model with a nonreflective boundary. A parabolic vanatlon of the medium properties is assumed, so that the boundary zone has properties sm~othly al:'proachin~ those of the outer zone to alleviate wave reflections from the interface between the two media. Vertically, t~rslOnally and radially excited soil layers have been examined in this paper. The results are evaluated over a wide range of the parameters involved and compared with those obtained for a homo~eneous layer, as well as compa~ed with Novak and Veletsos's solutions. Since this boundary-zone model Includes mass and a nonreflective boundary, the impedances (soil stiffness and damping) presented in this paper are considered to be more suitable to practical applications.