12. Design

Note for students

This chapter describes the design of primary flood protection structures. Although the description is largely based on the Dutch situation, the design approach can be applied abroad as well. The information in this chapter is to be studied as contextual material for the practical assignment. After studying this chapter on design of flood protection structures students are able to:

• Present the general logic of dike design;

• Apply the content of earlier chapters of the lecture notes;

• Discuss on design options in situations that are not standard.

The various processes involved in designing flood protection structures are described (Sec:des_proc). Over the last decades, these processes have become more and more important for the context of the technical design procedures. The chapter continues with the more technical design issues for dikes (Sec:crest_level_design, Sec:Geotech_design and Sec:des_piping). Designing a proper dike is a complex issue: safety standards are very strict, nearly all dike dimensions are technically interdependent and the requirements to fit the dike into its direct environment are multiple and often contradictory. The technical sections will give guidance to an iterative process in which the dike crest level is designed first Sec:crest_level_design, regarding the hydraulic boundary conditions. Secondly, the dike geometry in view of geotechnical stability will be established Sec:Geotech_design. Thirdly, the piping measures are relevant Sec:des_piping. From there we will explore options to fulfil environmental requirements and optimise costs keeping the primary function of the dike at the required standard Sec:opt_footprint. The final Sec:completingdesign on dikes covers the finishing touches of the design process by addressing the failure mechanisms additional to wave overtopping, macro-instability and piping.