Caissons bicycle cellar Amsterdam CS successfully installed
The transport of the three concrete caissons for the new bicycle storage facility for the IJBoulevard behind Amsterdam Central Station was successfully completed. The three caissons have been pre-built on the TMA Logistics site in the Western Port Area, about 12 kilometers from Central Station. By opting for transport by water, neither the city nor its travellers suffered any inconvenience.
The caissons are large elements: each weighing 6,500 to 7,000 tons, 30 meters wide and 5.5 meters high, with a length varying from 70 to 90 meters. In order to guarantee the watertightness, and therefore also the buoyancy, Strukton Immersion Projects pre- mounted the bulkheads in preparation for the transport. The first challenge of this transport was to leave the limited space at the port of TMA Logistics to sail via the North Sea Canal and the IJ to Amsterdam Central Station. The days of the transport have been carefully selected on specific days no cruise ship would arrive in Amsterdam. Due to good coordination and clear communication with Port of Amsterdam and thanks to the knowledge of North Sea Canal traffic, regular shipping experienced minimal disruption. After the transport of the caissons, the afternoons and nights were destined for aggravating the elements. Ballasting took place by the controlled lifting of bags of gravel (1,000 per element) and finally the inlet of water in the water tanks on top of the element. Strukton specialist Geocon monitored this process.
The connection of the elements to the posts is crucial. They are connected to each other with tie rods to prevent the caissons from raising up after the immersion operation. Specially designed rubber bearings were mounted on top of the posts, which are pressed down sufficiently by the weight of the elements to make this connection watertight.
On the 29th of November, the 2nd and 5th of December, the caissons were towed one by one to Central Station, positioned at De Ruijterkade and immersed the same day– an operation that took a total of around 48 hours per element and had to be carried out with a tolerance of 20 mm. Strukton Immersion Projects ensured that all elements were placed in the exact position on top of the piles.
The elements are now placed next to each other on the foundation piles with one meter between them. Strukton Immersion Projects is currently installing closing joint panels. When the joints are pumped dry the bulkheas will be dismantled. Once the bulkheads are removed the contract for Strukton Immersion Projects will be completed and Van Hattum en Blankevoort can start pouring concrete for the element connections and start the finishing works.