Evaluating the Impacts of Soil Layering on the Dynamic Response of a Structure

Soil and foundation compliance is known to impact the behavior of shallow founded structures during dynamic loading due to several related Soil–Structure Interaction (SSI) effects. Although SSI has been known in academic literature for many years, there is a wide variation in how (or even whether) it is considered during design. Recently, the use of commercially available 2D finite element (FE) analysis software has become increasingly popular, as the cost and time involved in running the software have decreased. In this study, the ability of 2D FE software to capture the effects of layered soil conditions on the response of a structure is investigated. Simplified elastic analytical solutions indicate that layered soils produce a higher frequency dependence and lower radiation damping compared to half-space conditions, which can potentially cause adverse effects on the structure. FE model results are investigated for various soil layering conditions and structural characteristics.