ABSTRACT
This chapter deals with the parameters that govern the strength of the flood defence: the crest level and the geometry of the dike and the soils strength and rigidity parameters. To situate the dike crest at design water level would be unsatisfactory. A certain freeboard is required. This freeboard has a number of important functions: prevention of serious wave overtopping; compensation for uncertainties in the analysis of the design water level; compensation for rises of the water level as a consequence of wind action; and so on. The geometry of the water-retaining earth body is not only of great importance for the stability of the dike but also for the way in which the load acts on the dike. The strength and stiffness properties of the soil can, as for materials such as steel, concrete, synthetics and others, be derived from the relationship between the normal and shear stresses and strain including changes in volume and distorsion.
