New floodgates Afsluitdijk

Sea levels are rising and so our Afsluitdijk must hold back more water. At the same time, the height difference between IJsselmeer and Wadden Sea is decreasing at low tide and the rivers carry more water. All this means that in future the existing sluices will not be able to discharge enough water to protect the dikes and harbours around the IJsselmeer. And so Rijkswaterstaat is initiating an impressive project. A project to which Safe is happy to contribute.  

To discharge more water, construction consortium Levvel (BAM, Van Oord, Rebel and Invensis) is realising two new pump groups. This work, part of the large-scale renovation of the Afsluitdijk, is currently underway. Once completed, the two new pump groups of three pumps each will discharge IJsselmeer water into the Wadden Sea at a capacity of more than 235,000 litres per second!

Concrete mass of some 4.6 metres!

The new pumps will come in a construction pit that Levvel realised at a depth of about 18 metres below sea level. The water pressure is enormous and so everything here is big and thick. So are the concrete decks of the approach shaft. Levvel asked Safe to help think about this; after all, not everyone is able to keep a concrete mass of about 4.6 metres in the air. In addition, the 'suction bells', part of the snail shell of the immense pumps, have to be supported locally. This, too, is no small challenge. These precast concrete ring elements weigh roughly 26 tonnes each and each pump has 4 of those rings! When the powerhouse is ready, Safe will continue towards the roof floor of the pump groups; 'only' one metre thick, but at a height of over 15 metres!

We are proud to collaborate on this project, which is as challenging as it is important. We provide the engineering in 3D and supply and assemble all necessary support structures, including slab formwork for this component. Good for 26,000^{m3 of} support and 2,600^{m2 of} timbered deck.