ClientMaarsen Bouw en Ontwikkeling (MBO) / Westerlaan CV
ArchitectEctor Hoogstad Architects, Rotterdam
Project sizeParking floors 9.800m2 GFA, approximately 350 cars
Start of project2006
Consulting servicesStructural design and engineering, supervision and administration
The shifted Westerlaan has been placed over the eastern roof deck of the garage, while the park has been extended over the western deck. Loads are, respectively, traffic class 60 with 0,5m sand or a maximum of 1,5m soil. Existing construction rested 2,7m away from the construction site’s eastern edge, while the Maas river banks were 35m away from the pit’s south side.
For the 103x33m2 construction site, a closed pit was built with an underwater concrete floor in order to minimize any drainage effects on the surroundings.
After an excavation—dry up until ground water level and wet until Amsterdam Ordnance Datum -8,4m—Vibro-Combi piles have been driven and a 1,4m thick layer of underwater concrete has been cast, all done with a crane moving traversal over the dam wall.
Consequently, the pit could be dried and the structural 0,7m thick concrete floor was laid to serve as a base for the skeleton. To reduce both the basement floor’s shrinkage and the risk of cracking, the floor’s heart has been provided with a cooling water piping system. This floor is anchored to the dam walls, which as a result have become definitive basement walls. The seams between the planks have been welded in order to make them waterproof.
The skeleton has been constructed with a maximal application of prefabricated concrete: prefabricated columns and walls, beam floors and wideslabs with in-situ cast pressure distribution layers. For the deck, the extreme upper loads had to be accounted for. The horizontal forces from the surrounding soil masses cancel each other out through the floors.