Delta Life 11

An alliance between Deltares and the business sector is producing innovative techniques and creating new market opportunities for enterprises. DELTARES, MARCH 2019 23 ICONIC AFSLUITDIJK BARRIER DAM GETS A MAKEOVER IMAGE: GUUS SCHONEWILLE 'The added value of the tests in the Delta Flume is that they clearly showed that the opti­ mal balance has been found between complying with the design requirements and the materials used.' Carlos Mollet , Levvel project director T he Afsluitdijk barrier dam split up the old Zuyder Zee, cutting off what is now the IJssel Lake from the sea. The aimwas to improve flood risk management and reclaim land.The completion of the 32-kilometre-long causeway in 1932 firmly established the global reputation of Dutch hydraulic engineering. The iconic dike is now being strengthened. The capacity for pumping water from the IJsselmeer to the Wadden Sea will also be increased. Rijkswaterstaat granted the contract for the work to Levvel, a construction consortium consisting of BAM, Van Oord and Rebel. Completion is planned for 2022 and all the parties will be drawing on knowledge fromDeltares for the project, which is a unique partnership between a research institute, the government and business. The changes to the development and geometry of the dike are being assessed to determine stability and the maximum permissible wave overtopping. That research is taking place in the Delta Flume. This Deltares test facility is 5 metres wide, 9.5metres deep and 300 metres long. The ten-metre-high wave board can simulate any wave pattern found at sea or in rivers. The section of the dike between Korn­ werderzand and the Frisian coast was tested between August and November 2018. The work here involves a revet­ ment consisting of Quattroblocks on both the upper and lower slope. Testing on the section between Den Oever and Kornwerderzand will end in late February 2019. Levvel blocks will be used on the lower slope because the load on the dike is higher here. These innovative concrete elements weighing 6.5 tons were developed specially for the Afsluitdijk. In addition to verifying the design for Levvel, Deltares is also providing the Dutch government with knowledge relating to discharge capacity, pumping and scour. The Afsluitdijk will be strengthened and it will soon be able to discharge more water out of the IJssel Lake into the Wadden Sea. Tests are being conducted in the Delta Flume at Deltares. KNOWLEDGE IN OPERATION