From the location of the work, it’s difficult to imagine that there will soon be two sheets of concrete 70 m long, 6 m wide and 2 m thick here. They then have to be inserted into position in August 2021. The preparatory work for the construction is currently underway. The first sheet piling went into the ground on the night of 14-15 September 2020. ‘We’re using a vibration-free method, pushing them in place’, says technical site manager Emiel Vergouw. ‘We’re doing the work at night to minimise noise nuisance and also to prevent the track from subsiding.’ The work will continue every night for almost two more weeks. ‘You will then be able to see the work island where we will be completing this job.’ A total of 30 sheets of steel piling will mark out the area, 160 m by 15 m, between two metro tracks. ‘We’ll soon be bringing cranes, concrete trucks and other heavy equipment into the area. We’ll then start construction. It will be precision work, as space is very limited and the metro service needs to keep running.’
Building in the final location
In early November 2019, we inserted the first roof section of the additional passenger tunnel, the Brittenpassage, into position. This work was done from Arnold Schönberglaan. The roof had to be lifted diagonally across the A10 and the railway tracks. The roof of the Brittenpassage will consist of a total of seven sections. ‘We’re building as close as possible to the final location’, says Vergouw. ‘For the two roof sections that we’re now building between the metro tracks, the advantage is that they don’t need to be taken across the A10 to be inserted. Of course, the disadvantage is the limited space. But that applies to nearly all parts of the Zuidasdok project.’
In order to be able to build two roof sections simultaneously on the work island, the ZuidPlus construction consortium, which is carrying out the work, had to come up with an ingenious idea. This is because there is no room for two work sites next to each other. The solution: the first sheet of concrete will soon become the work site for the second sheet. Vergouw: ‘In October 2020, we will start work on the roof section that will be under metro track 1. When that is completed, it will be covered by a protective layer of sand and become the work site where we’ll build the second roof section.’ This second section will be under railway track 4. So, when both are completed, we’ll push them southwards.
Few construction workers
The limited space is also challenging for another reason: not many people can work there simultaneously, around 24 construction workers. ‘It’s also to ensure social distancing (1.5 m)’, says Vergouw. By way of comparison: for the construction of the first roof section in Arnold Schönberglaan, there were sometimes hundreds of people working at the same time. Finally, there is the challenge of the firm deadline. ProRail, NS and GVB have adjusted their timetables so that reduced railway and metro services will be possible in the period from 20 to 23 August 2021. ‘The work on the roof sections cannot be allowed to overrun, because then it will take a long time before we can get our colleagues to schedule another adjustment to transport services.’ If everything runs smoothly, there will be one roof section of the Brittenpassage under railway track 4 and one under metro track 1 by the morning of Monday, 23 August 2021. By then, three sections of the roof of the Brittenpassage will be in position, with another four to go.