Delta Life 11

DELTARES, MARCH 2019 DELTARES IN BRIEF DELTARES SAVES THREE MILLION FOR AMSTERDAM When is a dike containing a pipeline strong enough? Amsterdam wanted an answer to that question when they were developing the Zeeburger Island district. The area where the new area is planned is already protected to the east by a dike. Because Zeeburger Island will be home to about 10,000 people in a few years, plans were made to install a pipeline for drinking water in the dike. In addition, the dike needs upgrading to serve as a primary water defence. That means complying with stricter safety requirements. It was assumed that a steel pile wall would be needed to protect the pipeline. Because it was difficult to determine the exact effects of the pipeline on the integrity of the dike, the City of Amsterdam asked Deltares to carry out a specific risk analysis. What did they discover? Everything is fine: the primary dike with the pipeline met the safety standards. Making it possible to save at least three million euros. REPLACING THE FOUN- DATIONS OF OFFSHORE WIND FARMS How can the foundations of offshore wind turbines – the monopiles – be replaced? And how can you do that efficiently, sustainably and safely? The first monopiles used in Dutch offshore wind farms are due for re- placement in 2030. Deltares is now looking at whether that can be done using hydraulic extraction. During the trial, which is being conducted to scale, we are looking at whether the piles can be, as it were, pushed out of the ground using water pressure. This approach is known as hydraulic extraction. The pile is closed off at the top and then sea water is pumped into it. In the end, the pressure in the pile, which is open at the bottom, squeezes it out of the seabed. The initial results of the research, which was conducted in an alliance with a range of partners, are expected in September 2019. A variety of dams and power plants are located on the banks of the Tennessee River in the United States. The power plants use the river water for cooling. The Tennessee Valley Authority (TVA), which manages both the power plants and the dams, wants to optimise the operating conditions without a possible rise in water temperature having a negative impact on ecology. By linking the Deltares software Delft-FEWS to TVA's own plant models, the world's first 3D hydrodynamic model has been developed that can accurately simulate all the factors that affect the temperature of the river. As a result, the TVA can now predict the downstream temperature up to two days in advance and take measures in good time when they are needed. SOURCE: TVA PREDICTING THE DOWNSTREAM TEMPERATURE