ClientDura Vermeer Vastgoed bv
Project size24.500 n2 bvo
Start of project2010
Consulting servicesStructural design, specifications, detail drawings and calculations
This 55 metres tall office building has a square shape with a void in the middle. The building contains nine storeys above ground level and three underground levels. Because of the varying shape of the floors, the building is technically highly complex. This is also due to the resulting cantilever of 14,4 x 16 metres. The cantilever is realised by means of a Vierendeel truss in the facades and an internal lattice, both constructed with steel. Since hollow-core slabs are applied, spanning a distance of 14,4 metres and resting on concrete inner cavity walls, the floors do not require columns.
The ground level in the area is at approximately 4,5 metres below Amsterdam Ordnance Datum (AOD), with ground water levels rising in the Pleistocene sand layer up to 3,2 metres below AOD. As a result, constructing a 3 metre deep basement would introduce the risk of cracks. To prevent having to construct the parking spaces above ground level, it was decided to construct a very deep basement, so deep that the building could be founded on the Pleistocene ground layers—as firmly founded as it would be on steel. To this end, a construction pit has been created with temporary steel sheetpile walls secured with grout anchors, and a two metre thick underwater concrete layer secured with vertical ground anchors.