A9: A project of the big numbers for Van Schaik Grondverzet

From a complete water management and reinforced soil to pile mattress and retaining walls. The variety of work being carried out by Van Schaik Grondverzet for the widening and deepening of the A9 is great, to say the least. Director Peter van Schaik: "In the past four years I have often thought 'this is Mission Impossible,' but still our men get it done again. That makes me really proud." 

In large infrastructure projects, Van Schaik Grondverzet is often asked for specialist earthmoving work. Such was the case for the widening and deepening of the A9 where VeenIX was responsible for the project on behalf of the Department of Public Works. It started with the question of whether Van Schaik could lay a section of sewer. We are now four years on and Van Schaik has completed an impressive list of assignments. "We work on the entire stretch," says Peter van Schaik, the second generation of Van Schaik. His father founded the company 55 years ago. Today it is a specialist in earthmoving in the broadest sense of the word. They have a large fleet of machinery and have the professionals in-house, from work planner to GPS specialist. "The work on the A9 is a super challenging job for us with a lot of variation. Near Amstelveen, the A9 will soon be sunken over a length of 1.6 kilometers. Here we first worked for two years on the bypass. We did the groundwork for the temporary bridges and took care of the complete water management with piping over a length of 5 kilometers. We do this entirely in-house." 

Lightweight

To realize the bypass, Van Schaik made a lot of piling platforms for the piling and sheet piling work. To do this, she moved about 100,000 cubic meters of soil to make sure the plateaus are level. "We also applied about 90,000 cubic meters of Argex pellets as fill material. This is a lightweight clay pellet and therefore very suitable for the weak subsoil near Amstelveen. But because it is lightweight, it is also quite challenging to apply. We specially purchased a light bulldozer for this purpose that can drive over it." As if this were not enough, the earth-moving specialist also supplied 900 cubic meters of water daily so that the 17,000 GWI anchors could be drilled into the construction pits.

80,000 cubic meters of EPS

Speaking of numbers: in addition to earthmoving for the bypass near Amstelveen, Van Schaik is processing more than 80,000 cubic meters of EPS at four bridges. "The EPS is ideal because it is lightweight, about a hundred times lighter than sand, and therefore it puts less strain on the subsoil." Van Schaik also supplies concrete riser plates for the various structures, 411 in total. These impact plates are used to create a smooth transition between the road and the bridge. They help to prevent any subsidence and height differences that may occur due to ground movement and traffic loads.

Race against the clock

One of the challenges within this project is time. "You're always working against the clock. It amazes me every time that things still work out. For example, a weekend closure has to be requested from the Department of Public Works a year in advance. We have an average of fifteen to thirty people working on the project every day, five days a week and at least twenty more weekends. All the work has to fit together like a puzzle. Moreover, making plans takes a lot of time, which reduces the execution time. The shorter the execution time, the more dependent you are on the employability of your people. If you then have to scale up, that is quite a challenge," says Van Schaik.

Network deployed

For Van Schaik, the A9 is clearly a project of large numbers. "Sometimes we're doing water, other times we're doing earthwork, then we're making a transmission line. No day is the same." Given the volume of work, the earth-moving specialist deploys its network of subcontractors. "For weekend work, we deploy extra equipment. Then, for example, we drive just like that with five mobile cranes, four tractors, two crawler cranes and four large shovels. Fortunately, we have colleagues who are happy to help. A good network is very important. If you can't share, you can't multiply," Van Schaik concludes.