The ground is naturally a non-homogeneous medium. In order to evaluate the earthquake response of the ground, it is necessary to evaluate the influence of non-homogeneity of soil medium. In this paper, a statistical methodology is presented to model the ground with non-homogeneity. Then, statistical earthquake response analyses of non-homogeneous grounds are conducted by using the Monte Carlo simulation method. As a result, it is clarified that the influence of dispersion of shear wave velocity is larger at small earthquakes, but the influence of dispersion of soil strength is larger at large earthquakes. The ordinary method used in the seismic design procedure, in which average soil properties are used without taking into account the dispersion of soil properties, provides the average value provided by the analysis that considers the dispersion of soil properties.

Copyright (c) 2001 Railway Technical Research Institute