'Each foundation pile can bear the weight of a hundred Indian elephants.'
Michiel Niens, Project Manager IMd Consulting Engineers.
‘The entire load of the building has to be supported where the depot is at its narrowest.’
Interview with Michiel Niens and Pim Peters, IMd Consulting Engineers.
The new depot has to be a safe and secure ‘strong room’ for artworks, but at the same time a building where people work and large numbers of visitors are welcome. IMd’s engineers were tasked with devising structural solutions that dovetailed seamlessly with the overall design.
How did you become involved in the design of the depot?
Pim Peters: We were among the firms Rotterdam City Council asked to submit a quote. At that moment the architect had not been chosen. So we were selected as consulting engineers before we knew what the building would look like. At the same time there was a competition for the design. Architects MVRDV won.
How did the design process proceed?
PP: Based on the winning design, we worked out a structural solution with a number of alternatives. We discussed them with architect Winy Maas of MVRDV, the principal and other consultants.
Michiel Niens: MVRDV works at a very conceptual level. Their architectural concept was like a bowl and so the building had to be built that shape. Everything that they and we as engineers came up with had to support that concept. The doors, for example, had to be made in such a way that they were consistent with the bowl shape. The architects of MVRDV had a number of ‘red lines’ that they considered important.
What was the depot’s biggest structural challenge?
PP: The building’s diameter is forty metres at ground level and sixty metres at the top. That means the building gets wider, and the overhanging part is not directly supported. Furthermore, there are openings in the lowest part of the building, which by definition make a structure weaker. Take, for example, the doors that lorries carrying artworks can drive through and an entrance door for visitors. The challenge was to devise a design in which the part of the building with the smallest diameter, which also has the most weak points, can withstand the high load.
MN: The forces in the lowest part are so large that we looked for a monolithic structure. That means that the bowl shape of the building is a slab edge on the foundations. The first two floors are made from concrete poured in situ. In fact, you create a solid plinth. When this concrete has cured, we construct the remaining four storeys of the building on top. These upper floors are made from prefabricated concrete elements.
What forces occur in a unique building like this?
MN: Foundation piles are driven into the ground underneath the building. Normally speaking a foundation pile can absorb a load of approximately 2,000 kilonewtons. We use piles for the depot that can support double, so 4,000 kilonewtons. To give you an idea of how much that is, an Indian elephant weights about 4,000 kilograms. Each foundation pile can therefore bear the weight of a hundred elephants.
How do you ensure that this challenging structure remains standing?
MN: You have to check the design calculations thoroughly, and also take into account sensitivities that can occur. For example, in practice a foundation pile can be a bit stiffer or weaker. It’s also important to know the weight of all the artworks stored in the depot and incorporate this information in the calculations. Then you’ll have a building that will certainly remain standing if it’s constructed according to our design!
Do special structural requirements apply to a building intended for art?
MN: The depot is in risk class 3, the highest risk class according to building regulations. This means that a comprehensive risk analysis has been made and bigger safety factors have been used. And needless to say, the starting point was that the artworks, which have huge cultural and economic value, will have a very safe home here.
Depot Journal
This article has been published before in Depot Journal #2 which is part of a series of six. If you would like to receive all the printed Depot journals by post, please send an email to info@boijmans.nl with your full name and address, reference ‘receive Depot Journals’.