Sinking a geofabric construction
 
As well as sinking foils in water it is also possible to choose to sink a geofabric construction. Genap has gained considerable experience with this during the project N242 at Alkmaar and with the sedimentation reservoir at Veendam. The principle is the same as positioning a foil construction, however the purpose and the material is different.
 
The purpose can be to place a protective layer under a foil construction to be placed later, as was the case with the N242 at Alkmaar. On the other hand, it is also possible to place a separation layer between the ground layer and the water as in the case of the sedimentation reservoir at Veendam.
 
The materials we choose for this is a 500 grams non-woven polyester. This is supplied prefabricated or composed on site and pulled across the excavation using a pulling strip and a winch system. The geofabric is sunk by pumping the water round.   
 

Sinking geofabric at Veendam
Genap B.V. Folieconstructies, by order of Arcadis Assen, successfully placed a geofabric construction in water at Veendam on Friday, 31 March 2006.
 
In contrast to the waterproof solution that Genap normally creates, a water porous construction was placed here. This was a Genatex Geofabric with a surface area of about 20,000 m². The geofabric was pulled across the water while floating as one prefabricated piece by means of a winch system. After the geofabric had been pulled across completely ballast was used to sink it. 
 
The geofabric formed a separating layer between the polluted sediment lying on the bottom and the sediment that was then added to the geofabric.