Frequency domain analysis of soil-structure interaction

In practical soil-structure analysis a number of basic issues need to be addressed. First, the soil-structure interaction problems are generally of a very large size. A suitable transformation should therefore be used to reduce the size of the problem. Second, analysis in the frequency domain, which is the preferred method for problems involving wave propagation in an infinite soil medium, usually requires the application of discrete Fourier transformation. The use of such transformation often leads to unacceptable errors caused by aliasing or overlapping. Analytical techniques that address these issues are presented here. A set of Ritz vectors based on the concept of component mode synthesis is developed for the transformation of the interaction problem. The method of artificial damping, developed by two of the authors, and reported earlier, is applied in the solution to avoid the problem of aliasing. The effectiveness of these techniques is illustrated by means of some examples of soil-structure interaction.