87-0010 Vertical and Torsional Vibration of Foundations in Inhomogeneous Media A.S. Veletsos and K.W. Dotson 1987 Rice University 48 PB88-134291 0 A study of the dynamic impedances for a radially inhomogeneous infinite viscoelastic layer with a circular hole, and for piles embedded in a medium represented by such layers is made. Systems in vertical and torsional modes of vibration are examined considering both a discontinuous variation in shear modulus and an exponentially increasing, continuous variation. The results are evaluated over wide ranges of the parameters involved and compared with those obtained for a homogeneous layer. In addition, the harmonic response of strip foundations supported at the surface of a vertically inhomogeneous viscoelastic halfspace is examined, and it is shown that within the framework of a previously proposed approximation, the impedances of such foundations for both horizontal and vertical modes of vibration may be deduced from those obtained for the vertically excited, radially inhomogeneous layer. Dynamic Structural Analysis, Soil Mechanics, Soil-Structure Interactions, Foundations (Structures), and Vibration.