Ski slope on the roof
In the eastern Buda Hills close to Hungary’s capital, Budapest, lies the popular nature and recreation area Normafa.
Data & Facts
Hillside sports centre blended into the landscape
In the eastern Buda Hills close to Hungary’s capital, Budapest, lies the popular nature and recreation area Normafa. Due to its location, this area is best known for winter sports activities. However, visitors who don’t want to wait until the depths of winter to put on their skis can look forward to the new sports and recreation centre.
This is being built close to an art nouveau villa that is more than 100 years old and nestles into the surrounding landscape. Located on a slope, the sports and recreation centre will be built below ground in several stages.
Underground water tank
First of all, a basement is located below ground with a floor area of about 2,000 m². This serves as a catch basin for rainwater, which can be used to run snow cannons if required and thus ensure that the slopes remain skiable throughout the winter. The structural requirement is thus clear: the walls must be watertight. The outer walls were thus tied from two sides with internal water stops. This is done by screwing a tie rod into the water stop from each side. The water stop is then left in the wall as a irrecoverable internal part after pouring. When using a water stop, two short anchor sleeves and four cones for plastic tube are also required in order to seal the tie hole (see figure below).
Single-sided tying with STB 450
The 100-meter-long building possesses three extension units that are also built into the slope. Thus, further storeys are located next to the rainwater catch basin, partially below ground. Their foundations are each at a different height. The steps between the floor slabs were poured against the earth wall using the STB 450 support frame. When using a single formwork wall, the entire fresh-concrete pressure is transferred into the support frame via the formwork. Walls that extended beyond the earth wall were subsequently tied from two sides. The wall formwork used was the Mammut 350 system, which thanks to the large area of the panels of up to 8.75 m² and a fresh-concrete pressure load of 100 kN/m², made large cycles possible and thus ensured rapid construction progress.
Live load consisting of earth and snow
The rainwater catch basin itself is situated completely underground. Later on this will be covered by a practice ski slope. This extraordinary requirement was taken into consideration accordingly during the planning: The structural calculations were based on a roughly 30 cm thick layer of earth, the weight of the snow cover and, of course, the weight of the skiers themselves. The basement roof is supported every five meters by circular columns so that the calculated loading can be taken up with a slab thickness of 25 cm. The columns with a diameter of 30 cm were formed using MEVA’s Circo circular column formwork.
Slabs with an inclination of 25°
Overall, the new building situated on the hillside was designed so that it blends into the terrain. For this reason, several roof slabs, for example in the ski slope area, were formed at a 25° angle. Thus, some storeys disappear below ground and provide the skiers with more space. The MevaFlex slab formwork used was supported by EuMax props. With extension lengths from 90 cm to 550 cm, the MEVA props can be flexibly adapted to suit different heights, and thus also fulfil the requirements of this project.