Stiffness Coefficients for Layered Media

For dynamic soil-structure interaction problems, the soil resistance is often represented through a combination of springs and dashpots that assumes the soil is homogeneous. Often, however, the supporting medium is inhomogeneous, comprising layers of varying strengths and stiffness. An approximate method is presented to determine stiffness coefficients for layered media. The basic assumption made in the analysis is that the stress distribution in a given layer is a function only of the distribution of the applied load and is independent of the relative stiffness of the other layers. Therefore, all the layers can be determined by assuming that the material in one layer is identical to that in the other levels and the stiffness coefficients are computed accordingly.