How do you move 830,000 cubic metres of earth for the A10 tunnel?

830,000 cubic metres of earth: it is enough to fill approximately 330 Olympic swimming pools. This is how much earth is being removed in order to build the tunnel for the A10 Zuid, on which work will start in 2027. Of course, it will not all be removed at once, but gradually over a three-year period. We also intend to transport it away as efficiently as possible, without causing too much disruption to the local area or to construction work. ‘As part of the design phase for the tunnel, we’re investigating two methods: pumping the earth away by means of a system of underground pipelines or transporting it using trucks. Both methods have their pros and cons’, explains Ton van der Steen, project manager for contractor VolkerWessels.

According to Van der Steen, the option of removing the earth for the tunnel construction by means of hydraulic pumping has been explored in some detail. It is a method where you pump in water via a pipeline and then mix that water with the earth. This creates a mud-like substance that can be pumped away via a different pipeline. ‘Of course, that’s a great solution from a logistical perspective as it reduces disruption to the road network and the construction site. But there are also downsides. We’ve explored the option of pumping it all the way to the Nieuwe Meer lake. That would involve laying pipelines across a large area for a period of several years. We would then clash with other Zuidasdok projects, such as the extension work on the Schinkelbrug bridge and the widening of the A10-Zuid.’

Transporting the earth by truck would therefore appear to be the more realistic option. ‘Compared to removal by boat, using trucks gives you quite a bit more flexibility’, says Van der Steen. ‘A boat can’t just sail in a different direction, but a truck can opt for an alternative route. Upscaling is easier if it proves necessary and it is also financially more attractive than hydraulic pumping. Of course, there are also disadvantages – don’t forget: you’d need 55,000 trucks to transport 830,000 cubic metres of earth. All of those trucks would have to travel by road.’

In addition to the transport, there is also the issue of what to do with all that earth. The current plan is to use some of it – if it is clean – for the construction of the last island in IJburg: Buiteneiland. This island will be about the same size as Vondelpark, with space for sport, nature and leisure, and is likely to be completed sometime between 2045 and 2050. Van der Steen: ‘A dike has already been laid around the future island, but more earth is still needed to fill it and raise the height of the island. Of course, it would be really great if the earth from the tunnel could be put to good use in a circular way.’