Hydraulic stability, damage processes and prevention strategies for coastal protection structures at contact and transition points

Brief description

Dikes serve to protect nature and people from flood events. In their function as hydraulic engineering protection structures, their functional efficiency must be guaranteed at all times. Material boundaries and transition areas on dikes - e.g. material transitions from stone, concrete or asphalt to grass - are particularly vulnerable dike components. As a result of increased hydraulic load and locally reduced resistance in the transition area, these can represent a particular hazard during load and, in the worst case, lead to the failure of the dike. Thus, during storm surges, the onset of damage is often initiated precisely at these discontinuities by contact and joint erosion. Although these transition areas have already been identified as weak points, design guidance is available only for selected transitions, and, moreover, all of it is based on empirical values from practice and has not been systematically investigated or analysed, yet.

The aim of the HyStKon project is to analyse the relevant hydraulic parameters and prevailing processes during the initiation and progression of damage and to develop recommendations for the design and optimised construction of material boundaries and transition areas. For this purpose, an inventory of existing transitions and damage patterns that occurred on dykes is carried out. Selected material boundaries and transition areas are then modelled, the damage initiation and processes within the framework of medium- and large-scale physical model tests (GWK) are analysed the hydraulic limit states are identified. Suitable solutions are published in a catalogue of measures for the design of contact and transition areas.