Analytical frequency-dependent infinite elements for soil-structure interaction analysis in two-dimensional medium

Analytical frequency-dependent dynamic infinite elements are developed to model the far field of a two-dimensional layered half-space soil medium for soil-structure interaction analysis. Using the proposed infinite elements, the element mass and stiffness matrices can be obtained in analytical forms of frequency and constant matrices representing the wave propagation characteristics in the far field soil medium. The compliances of rigid strip foundations on a homogeneous half-space, on a layered half-space, and on a layer strip with rigid bedrock are calculated using the present formulation, and the results are compared with those by other approaches. The comparison indicates that the proposed infinite elements give accurate solutions. The equation of motion including the present frequency-dependent dynamic stiffness matrix for the far field region can be analytically transformed into a time domain equation, and the soil-structure interaction analysis may be carried out in time domain. (C) 1999 Elsevier Science Ltd. All rights reserved.