Client and contractor investigations into the Eindhoven Airport car park collapse last year failed to correctly identify the cause of the incident, according to a report published by the Dutch safety board.
The car park was under construction and collapsed on 27 May last year when it was a month away from final delivery. No workers or passers-by were harmed.
A new report, conducted by the Dutch Safety Board, criticises client Eindhoven Airport and main contractor Bam for findings they each presented in separate investigations into why the collapse occurred.
Bam and Eindhoven Airport concluded that the collapse was caused by “a defect in the wide slab floor”, but the Dutch Safety Board has ruled that failure to understand the building’s floor design was actually the “direct cause” of the collapse
The Dutch Safety Board is an independent body which often investigates situations in which public safety depends on third parties, such as the government or companies.
Its report on the collapse states: “Both of these investigations stated that the direct cause was a defect in the wide slab floor; namely, imperfect adhesion between the floor slabs and the concrete that was subsequently poured over the top.
“However, the Board’s investigation revealed that this imperfect adhesion was not the cause, but rather the consequence of the floor design selected for this building.”
“The collapse was the result of the design decision to rotate the ‘BubbleDeck’ slabs in the floor of the parking building one quarter-turn in respect to the orientation in which they are normally used, without recognising the consequences of this change.
“The main result of the decision to rotate the slabs was that particular attention needed to be paid to the seams between the floor slabs. Such attention was not paid, however, with the result that insufficient reinforcement was given to the connections between the floor slabs at the level of the slab seams.
“The floor was thus unable to bear the loads. The floor was so vulnerable that the slight increase in the load on the floor resulting from the high temperatures on 27 May 2017 was enough to cause the floor to partially buckle.”
In addition, the report also explains that there were clear indications of structural safety problems during the tendering process and in the implementation phase.
“At that time, none of the parties saw these signs as a reason to call the structural safety into question, although they could and indeed should have done so,” the report adds.
The Dutch Safety Board’s report also accuses the country’s construction industry of “not adequately learning” from incidents such as the collapse.
The report states: “Clients and contractors in the industry still too often treat each construction – and thus each incident – as unique, meaning that they think the lessons do not apply to them. Because of this, the same underlying processes can result in (structural) safety incidents over and over again.
“In addition, it is apparent to the Board that a blame culture exists. After an incident, parties in the industry appear to be more concerned with deflecting blame than with focusing on how they themselves can contribute to improving safety. The often defensive and legalistic form and undertone of the responses received by the Board to its draft report exemplify this attitude.”
Issues identified by the Dutch Safety Board to improve structural safety:
- Tasks and responsibilities on construction projects must be clearly distributed
- Ensure that in practice the lowest price is not put at the at the expense of the risks being sufficiently understood, mentioned or priced
- The construction industry must be willing to learn and to engage in self-reflection
- Government oversight of the Dutch construction sector must be more effective
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