Proven Delivery
Antwerp North South Link Tunnel
Located in the densely populated city of Antwerp, each of the bored tunnels was 2,456m long with an outside diameter of 8.0m
Wayss and Freytag
Wayss and Freytag were main contractor in joint venture and this contract was one of three to create the link tunnel. The project comprised the detailed design and construction of two single-track railway tunnels between Astrid Square in front of Antwerp Central Station and Dam Square in the north of Antwerp. The contract also included the construction of a double-track covered access, three emergency exits for both tunnels, an arrivals complex underneath a metro station and two cross passages.
Cross passages were built between the tunnels every 300m and were constructed using the pipe jacking technique. An open cutting sleeve was used under the protection of a lowered groundwater table and the passages were linked to the tunnel tubes by means of steel segments.
The tunnel passed under buildings with a clearance of only 4m between the foundation of some of the buildings and the top of the tunnel roof. To protect the buildings, a pipe-roof support system consisting of 1.2m diameter tangent reinforced concrete pipes was installed ahead of the tunnel drive using the pipe jacking technique. The pipes were jacked forward from a shaft and then filled with reinforced concrete.
Other challenges included tunnelling under an existing metro tunnel with a clearance of only 40cm where settlement had to be prevented by high quality driving work and under Astrid Plaza Hotel with very little clearance between the tunnels.
On time and on budget
All the key dates were met, including the project completion date and the sectional completion dates. The project was delivered within the target cost and the tunnel driving work was completed four months ahead of schedule.
