Straight after the eight-day closure of the A10 Zuid in the summer of 2023, the Nieuw-Zuid Construction Consortium (BCNZ) embarked on a mammoth job: excavating the Brittenpassage. After four years spent building the roof of the new passenger tunnel for Amsterdam Zuid station, it was finally time to remove 50,000 cubic metres of sand from underneath the motorway, metro and railway tracks. The work proceeded at pace. Where for years all we saw was an embankment, in September the contours of the future passageway suddenly appeared.
In December, the BCNZ construction team reached the required depth on the south side of the Brittenpassage, as the above time-lapse video shows. But also in October and November, there was all sorts of activity to be seen in the passageway on our webcam. Take a close look at the height differences in the videos.
The first visitors
In October, the first group of interested parties had a look ‘below deck’. In 2027 at the latest, when the Brittenpassage opens, they will be able to say they were one of the first visitors to have walked through the passageway.
Of course, the work not only involved digging – we also had to install endless amounts of sheet piling in order to prevent the sand from collapsing inwards during excavation work. This proved quite a challenge, because some sections needed to be inserted around 23 m into the ground within a passageway just a few metres in height. We therefore inserted them into the ground in 1.8 m sections, which we then welded together.
Drilling in tieback anchors
In order to prevent the walls from collapsing forwards, they needed to be reinforced. We did this by installing two rows of tieback anchors, a type of lateral foundation pile. These were drilled in just before Christmas, after which they were able to harden. We are currently post-tensioning the final anchors.
Pumping and more digging
Because the south side of the passageway is now largely at the right depth, we have been able to start installing foundation piles for the floor of the passageway. In mid-January, we will install the pumping system that will be used to pump away excessive groundwater. We will then be able to continue digging locally, including in the places where we are building large footings that will ultimately support the columns of the passageway.
The final roof section is a reality
Meanwhile, in November, we worked above ground, between the metro tracks, on the construction of the seventh and final roof section for the Brittenpassage. This was precision work, because we were working just a few metres from the tracks on both sides. But it was successful and the roof of the new passageway is a reality. Five of the seven roof sections are already in position and the last two will be moved to their final location in the summer of 2024. After that, excavation work can also start on the north side.
The work goes on
Of course, we have no plans to be idle in the months ahead and will continue to keep you posted on works in the Brittenpassage. For details, keep a close eye on our website or come and take a look at our recently updated Information Centre.