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2012.07.04
tHe COLumNS
The concrete slabs are supported on a series of round columns with a uniform diameter.They are designed to absorb all the verti- cal force applied by the slabs and to reduce the bending moments to a minimum. All the columns are hinge- xed, so that they can follow the free expansion of the concrete slabs.
The diameter of the columns was kept to an absolute minimum: just 30 cm.The columns at ground level and on the rst oor are made from concrete- lled steel. On the second oor they are made exclusively of concrete.To allow for an ef cient use of space in the car park, the columns are positioned in a square grid of 8.1 m by 8.1 m.
The typically rolling landscape of the surroundings was not affected by the construction of the building.The sloping gradients were allowed to continue under the building, so that headroom within the car park is variable. In other words, cars simply park
on the undulating landscape. All the supporting columns have the same length (5.8 m between the foundations and the underside of the concrete slab).The bases of the foundations are all set at the same depth, so that some of the columns are deeper underground than others.
Where headroom is suf cient, the car park under the building can be extended in a later phase by using an additional split-level.
The structural calculations have been made on this basis.
One particularly noteworthy detail is the connection between the hinge- xed columns at the car-park level and the load-bearing concrete slab at the rst oor level. A steel pin with a diameter of 42 mm is the only physical connection between the column and the oor plate.
The hinged working of these bracing columns is ensured by resting the concrete slabs on neoprene rubber mats 70 mm thick, posi- tioned on the column heads.The neoprene rubber mats also have insulating qualities, so that they prevent thermal bridging in the building envelope.The heat losses which might otherwise occur at the point of contact between the pin and the concrete consequently have no effect on the K-level of the building. In other words, it is almost as if the rst and second oors ‘ oat’ on the neoprene rubber mats, while the steel pins hold the building in place.
2012.09.08