Construction
The sandy foreshore is constructed after the installation of the sheet pile wall that encloses the design. The sand for the pilot project is retrieved from the Marker Lake, within 1km from the project site. When the sand is dredged, the hopper vessels are emptied by an excavator and the sand is fed to a soil pump installation. The soil pump mixes the soil with water and transports the sand/water mixture to the shoreline. The soil pump installation is moored 300m from the shore where enough draft is available for the hopper vessels to come alongside. At the project site a spraying pontoon is used to spread the sand and form the sandy foreshore. When the section was accessible for land-based equipment, the section was profiled according to design.
The complete construction sequence is summarized below:
- Installation of the sheet pile wall (from a pontoon) to enclose the sand body, provide construction site access and to fix monitoring equipment
- Dredging and placement of the sand volume of ~70.000m³
- Profiling of the slopes according to design
- Application of Holocene material for the purpose of vegetation growth, volume of ~2.500m³
- Application of the reed fixation matts and reed plants at the water line (16m wide and 100m long)