25 September 2017 - 10:02

Investigation results known of technical cause partial collapse Eindhoven Airport parking garage

Onderzoeksresultaten bekend van technische oorzaak gedeeltelijke instorting parkeergarage Eindhoven Airport

Bunnik, the Netherlands, 25 September 2017 – Today, the results of the investigations into the technical cause for the partial collapse of the P1 parking garage under construction at Eindhoven Airport on Saturday 27 May 2017 have been announced. In the past months the Netherlands Organisation for applied scientific research TNO, on behalf of Eindhoven Airport, and engineering consultant Hageman, assigned by BAM, have investigated the technical cause for the collapse. The conclusions of these investigations are aligned and clear.

The parking garage was constructed using BubbleDeck floors. These consist of precast concrete floor slabs and are equipped with weight-saving plastic bulbs. After installation on site, a concrete topping was applied.

The investigations show that the shear strength of the interface between the precast concrete floor slabs was insufficient to convey the traction. As a result, the structural capacity of the floor was compromised. The high ambient temperature on the day of the collapse was a contributing circumstance to the defect manifesting itself.

Construction standard

The assumptions for the design and calculation of concrete structures are described in the construction standard NEN-EN 1992-1-1. In addition to the investigation it has been found that both structural engineers and building inspectors in the application of precast concrete floor slabs generally do not adequately recognise the importance of shear strength for the adhesion of the floor. An additional guidance of the NEN-EN 1992-1-1 would certainly promote the application of the standard.

Significance for the construction industry

BAM has shared the conclusions of Hageman's research with Eindhoven Airport and the Dutch Safety Board (Onderzoeksraad voor Veiligheid), as well as with the wider construction industry.

Next steps

Further discussion among all parties involved will have to determine what will happen with the building and who can be held responsible for the incident.

Jaap Hazeleger, director of BAM Bouw en Techniek: ‘Fortunately an event like this is highly exceptional. We are very grateful that no personal accidents have occurred. With the investigation results in hand, we will engage in further talks with Eindhoven Airport to determine the most appropriate follow-up steps.'

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