The quayside time bomb
Amsterdam's 205 km of quayside structures are built on wooden piles on soft peat-clay subsoil; some are over 300 years old. They also have to deal with modern urban use, such as parked cars and heavy lorries, and the effects of climate change. If something goes wrong with their construction, a so-called failure mechanism, the risk of collapse is imminent, as happened to the Grimburgwal in 2020.
Because of their age, for many quaysides there is no documentation about their structure; and there is no easy way to test how safe they are. So how does the city decide which structures to repair first, and how quickly?
Controlled destruction
To understand the failure mechanism of historical quaysides, the project undertook a unique experiment on the historic Overamstel quay, which dates back to 1905. By applying various loads to the quayside, and using sensors to gather data, the failure of the pile foundations was tracked and measured. From this data a computational model was developed to precisely predict which quaysides are at risk of failure.
Immediate practical value
The research found that horizontal failure of the wooden piles under an historic quayside is most likely to occur when there is a sidewalk or road at the back of it which has to carry loads like parked or moving cars, heavy vehicles, or goods/building materials. The resulting computational model is 40% more accurate in identifying quaysides at risk of failure than previous models. The City of Amsterdam now has a highly accurate tool to identify safe and unsafe quayside structures, greatly helping it plan and budget for their repair. The tool is not only relevant for Amsterdam, but also for the 1700 km of quaysides across Holland, as well as other cities with historic quaysides, like Venice and Barcelona.