Deformation and strength of embankments on soft Dutch soil

Embankment and dyke stability in the Netherlands has always been evaluated by effective stress analysis. The subsoil of most of these structures is organic, weak and soft, but the internal friction angle of these soils is surprisingly high. Empirical methods are used to obtain acceptable, reduced values of friction angle from triaxial tests for use in stability analyses. It appears possible, however, to do full justice to the peculiar combination of low strength and stiffness and high friction angle by means of the finite-element method using a viscous version of the Cam-clay model. All parameters of the model are found from a single test in a constant-rate-of-strain K₀ oedometer. The approach is illustrated by two case histories, after first providing insight into the peculiar properties of the Dutch soils, and the manner in which they are dealt with.