9 - Soil–structure interaction for seismic analysis and design of bridges

Abstract

This chapter provides a review of recent developments in the field of soil–structure interaction (SSI) in terms of relevant aspects of the analysis and thus the corresponding impacts on seismic design of existing and new bridges. The structural response is particularly attributed to the soil–structure interaction forces that have an impact on the bridge structure. Realistic modeling of the bridge foundation system influenced the prediction of the superstructures response significantly. Analytical procedures and modeling methodologies for seismic response studies are regularly revised to develop a more effective design of structural detail. The practice of geotechnical engineering involves estimating the effect of local soil conditions on ground motion. For extended long-span bridges, the consequences of local site conditions become of particular importance because the spatial variations of ground motion will cause multiple support excitations of the bridge structure. These spatial variations are the result of a combination of local soil conditions and other mechanisms related to wave propagation across the Earth’s crust. Understanding the interaction of global soil structure in bridges is essential for capturing their performance during a major seismic event.