Successful Easter weekend of work on Zuidasdok

View the time-lapse video of the work:

Coordinating Construction Manager Emiel Vergouw looks back on a successful ‘Easter weekend of work’. ‘It went really well’, says Vergouw. ‘It just shows you how important good preparation and effective collaboration are on the building site.’ The ZuidPlus construction consortium team started the job on Thursday, 1 April 2021, the main part of which involved building the foundations – or abutments – for the two new roof sections that will be inserted into position in August. These are two of the total of seven roof sections for the new passenger tunnel – the Brittenpassage – at Amsterdam Zuid station. ‘In the last few days, we also widened platform 3-4 and, because of that, added a bend to railway track 4. What’s great is that passengers can immediately benefit from our work, because they have more room to move around on this platform.’

The work went more or less according to schedule, with only the occasional minor setback and the odd stroke of luck. ‘Because railway track 4 and metro track 1 had to be usable again by 05.00 on 6 April, we built in a little extra time in order to be on the safe side’, explains Vergouw. ‘The first job, involving removing the tracks, went according to schedule, but removing the scaffolding from the temporary platform next to work pit 1 proved more difficult than expected.’ Work pit 1? ‘Under the removed track and platform, there are 4 ‘work pits’ where previously inserted foundation piles are. We had to expose these foundation piles by digging up 1000 m³ of sand using machines.’ Despite the huge amount of sand – the equivalent of 12,500 fully-filled wheelbarrows – this actually went really well. ‘That meant we were able to catch up on lost time on Friday, 2 April.’

And, one by one, they appeared: the foundation piles. The piles in the outermost pits serve as the foundations for the abutments, the construction of which began on Friday evening – right on schedule. ‘An incredible job’, says Vergouw. ‘Everyone stopped work to watch how the huge steel structures – four in total – were hoisted one by one into position. Not only was a huge reinforcement cage dangling in the air like that an amazing sight, it was very much touch-and-go whether the cages would fit properly onto the positioned foundation piles. Incidentally, we also had the weather on our side, as we needed to avoid heavy winds, like the ones we saw during the construction of the previous abutments. But fortunately, it all went perfectly well this time around. Obviously, that gives you a real boost.’ But there was not much time to stop and admire the successful operation. ‘After that, we immediately had to start pouring the concrete into the reinforcement cages and the abutments were complete.’

The fact that some of the foundation piles are slanted is not down to sloppiness. ‘Absolutely not’, says Vergouw. ‘They are deliberately slanted – we call them batter piles – in order to accommodate the braking power of a train. Together with the abutments, these piles not only have to bear the weight of a piece of roof, but also the force of the trains passing by on top. When trains or metros are braking, these slanted piles, which are clumped together, ensure that the deck remains stable. In other words, these piles are deliberately slanted.’

The two innermost foundation piles will not have any abutments since their role is to support the 70 metres long central roof sections. ‘The deck’s too big and too heavy to be supported by the ends only and without some assistance in the middle, it wouldn’t have sufficient support’, explains Vergouw. ‘However, that support won’t be needed until we excavate the Brittenpassage to create the new passenger tunnel.’ In the future, passengers will also be able to see this support in the form of columns in the tunnel. The foundation piles also serve another function. ‘In August, we will be placing the special structure onto them that we’ll use to manoeuvre the two roof sections into position.’

On Sunday, the so-called facing walls were the final part of the foundations to be added. It was possible to fit these onto the abutments on Sunday, when the concrete had hardened. They serve to separate the structure from the ground behind it. Vergouw: ‘In August, we will insert the ends of the two roof sections, each 1 metre thick, 70 metres long and 4 metres wide, into the exact position above the abutments between the facing walls.’

You can view Marcel Steinbach’s photos of this work here.