Energy Academy Europe: most sustainable quake-resistant education building

The newest acquisition to the University of Groningen’s (UG) Zernike campus was built in the record time of 18 months. It is the Energy Academy Europe building, the most sustainable education building in the Netherlands, and named the most attractive new building in the city. And it can withstand earthquakes.

Not only was Energy Academy Europe the first education building in Europe to be awarded the BREEAM Outstanding certification in 2017, in March it also won the Mixed Use & Other Buildings category of the BREEAM Awards 2017. And this summer, on Groningen Architecture Day, it was elected as the most attractive new building in Groningen by both the public and professional juries, despite – or perhaps because of – the fact that the architects had opted for a low-tech approach. In the UG alumni magazine Broerstraat 5, journalist Bert Platzer interviewed architects Aldo Vos from the Rotterdam firm Broekbakema and Paul van Bussel from Unie Architecten in Groningen. Vos had this to say about quake-resistant construction:

Redesign

'Form follows climate', explains Vos, by analogy with the architectural principle of ‘form follows function’. However, the building had to follow not only the climate, but also earthquakes. In the aftermath of the severe earthquake in Huizinge in 2012, the government drew up guidelines for earthquake-resistant construction, which were completed at about the same time as the building’s design. As the client, the UG wanted to ensure that the building complied with the guideline and the design therefore had to be drastically revised. 'The concrete stability cores, which contain the stairs, lifts and toilets, were too rigid, which would cause too many stresses in the building during an earthquake,’ says Vos. 'We replaced them with large discs so that the building could better absorb the vibrations. We originally had a concrete fa ç ade, but that would collapse in an earthquake. So we created a light, timber fa ç ade instead. All interior frames were designed with special joints to prevent the main load-bearing structure from behaving in an unpredictable way.'

Earthquakes

But the designers and builders had to solve many other technological problems as well. The new NAM guidelines also had to be applied to the special roof to ensure its stability. The sunlight that enters through the triangular glass panels in the roof and the predominantly glass fa ç ades usually provides enough light for the building during the day. The LED lighting doesn’t come on until dusk.
A sloping roof that is half constructed of glass posed enough structural challenges without the added risk of earthquakes. More stringent requirements were therefore imposed on the glass panes and their frames. The glass had to be ultra-hardened and multi-layered to make it earthquake-resistant. And deeper rebates were needed to prevent razor-sharp panes of glass from being dislodged and crashing down during the tremors.

The design challenges arose from the fact the building’s hard cores, such as the stairwells and lifts, from which the roof is suspended, are not all the same height because of the roof’s sloping structure. This difference in height means that they could move in different directions during an earthquake, causing the roof to fall. This risk was overcome by creating concrete and steel walkways and stairs between the fixed cores, so that they will all move in the same direction during a quake.

Vibration-free construction

Thanks to a special technique, users of the surrounding buildings have not experienced the noise and vibration nuisance that is normally associated with building solid foundations. The piles on which the Energy Academy Europe is built have not been driven into the ground. Instead, deep holes were first drilled into the sandy soil, which were then reinforced and filled with concrete. The hardened piles were then dug out and used as a solid foundation.

‘Groningen-type earthquakes’

The earthquakes that occur in Groningen are of a unique kind because they are induced by gas extraction. They therefore have a different impact than the tectonic earthquakes that are triggered by natural fault lines in the earth’s crust, as happens in Japan for example. ‘Groningen-type earthquakes’ are often short and sharp, with vertical acceleration (compression waves) being followed by horizontal acceleration (shear waves). This can cause more damage than a comparable natural earthquake. The Richter scale is not an appropriate measure here. What matters in Groningen is the impact of the peak ground acceleration.

The Energy Academy Europe is one of the first buildings in Groningen designed to be earthquake-safe. In the event of an earthquake, six seismic walls will absorb the energy of the tremors. The building will move flexibly around these solid, seismic cores. Other special features that make the building earthquake-safe, in addition to the ultra-hardened, multi-layered glass, are the walkways in the atrium, which link various construction components, and a roof that can move as a whole. Many gaps (dilatations) have been incorporated into the structure to give the columns, floors, window frames and windows room to move.

Fenneke Colstee, UG Communications