Incorporating small-strain stiffness into geotechnical analysis

The nonlinear soil behavior at small strains is often neglected in geotechnical analysis. Doing so often leads to an overestimation of foundation settlements and retaining wall deflections. Settlement troughs behind retaining walls or above tunnels on the other hand may be analyzed to flat and extended. Comparing measured displacements of piles or anchors within the working load range to those calculated without considering small-strain stiffness shows a considerable too soft response. This paper is concerned with a qualitative and quantitative discussion of the small-strain stiffness phenomenon. In combination with the introduced commercially available numerical tool of the small-strain stiffness model, it provides the basics for incorporating small-strain stiffness into routine design.