Soil-Structure Interaction Analyses for Seismic Response

It is noted that significantly different results may be obtained by half-space and finite element analyses of the same soil-structure system. However, it is also shown that wide variations in results may be obtained by either approach alone depending on the details of analytical techniques used and the method evaluating appropriate soil properties. It is suggested that the major limitation of finite element analyses is the current inability to evaluate three-dimensional effects, while the major limitations of half-space approaches are that material damping effects in the soil are not considered, analyses are not available for multilayered soil deposits and the effects of adjacent structures are not usually evaluated. It is concluded that, at the present time, finite element analyses provide the best prospect for evaluating the probable behavior of soil-structure interaction systems. However, half-space analyses will often provide adequate evaluations for structures located near the ground surface.