Chapter 19 - Numerical models in geotechnics including soil-structure interaction

Abstract

Incorporating realistic soil-structure interaction (SSI) in built environment and major infrastructure projects provides significant beneficial role in terms of economics (i.e., better cost benefit), thereby reducing carbon footprints and enhancing green credentials. Generally, SSI is ignored, and often engineers tend to use Winkler's springs to decouple geotechnical analysis and structural analysis. The use of structural springs to mimic soil behavior (both linear and nonlinear) will have limited applications as in many cases we find that the springs do not replicate the actual soil behavior. Use of continuum stiffness somewhat deviates from 2D springs and brings better distribution of forces in 3D analysis. This chapter highlights how SSI can be applied to massive foundations, including nuclear reactor buildings. It also gives advice on how to verify the results using simple models. It is also important to understand the construction sequence and construction process before the results of the SSI can be effectively used in designing the reinforcement in concrete foundations. The current commercial packages that model nonlinear soil constitutive models although have beam and plate elements for modeling, the structural elements do not give satisfactory results for design. Therefore, this article focuses on how designers can overcome this issue and determine the forces in the structure from SSI. Structural engineers need forces to determine the steel and geotechnical engineers need to understand how to model the structural elements in SSI packages. This work gives some examples of major projects and gives guidance to the designers.