For the new Metro Line


Aarsleff Rail A/S in cooperation with Aarsleff A/S has completed a transfer tunnel and an elevator connection between the new metro line Cityringen and Copenhagen Central Station.

The project has required complex excavation and construction work under the heritage listed Central Station.


Because of a high groundwater table and railway in operation, the connection between the Central Station´s platform tunnel and the Metro Station under Reventlowsgade, presented several demanding challenges. Copenhagen Central Station is Denmark´s second busiest station and is built in an area with high groundwater table and difficult soil conditions. This is partly due to the fact, that the subsoil is made of old seabed.


In connection with this project, we used the experience gained from our previous major station renovation projects in Copenhagen: Copenhagen Central Station, Nørreport and Østerport Station, particularly in regard of handling complex construction projects close to heavily trafficked stations. In cooperation with Per Aarsleff A/S we established a system of pumps and reinfiltration wells to keep the excavation dry. The groundwater was passed through a sand filter, before being re-infiltrated or led to the sewer.


Completed in 5 main stages

The project was been divided into five main stages with focus on the strong interaction between the different tasks.

First, we dismantled part of the heritage listed building, to enable us to carry out jet-grouting and the establishment of a groundwater lowering system. Stage 3 consisted of excavation of the building pit complete with bracing structure, after which we constructed the tunnel itself in concrete.

This was followed by installation of tile cladding, technical installations and elevator system. Finally, we re-established the building over the tunnel according to drawings and photo documentation.


We have used special machines designed for the low height clearance under the Central Station and under difficult circumstances we carried out jet grouting, installed steel sheet piling and replaced existing wooden pile foundations to reinforced concrete mini piles.

In addition, we utilized a number of special machines to remove the existing DSB transfer tunnel.


The entire project has been continuously monitored with special attention to track, buildings and excavation. In addition to this, the project has been under close surveillance of Banedanmark and the Agency for Culture and Palaces to ensure the intactness of the protected buildings at the Central Station.


Management of external interfaces

Through the project’s phases we have handled a number of interfaces with e.g. cable owners, road authorities and neighbouring projects with the same access road. Furthermore, we have collaborated with train operators, building (DSB/ISS) and infrastructure owner (Banedanmark).


In connection with the work on the T7 contract, we also carried out the replacement of a number of load-bearing 12 m wooden beams in Douglas pine the owner of building (DSB),



  • Dismantling and reconstruction of a heritage listed building
  • 1.700 m3 excavation for the tunnel and handling of contaminated soil 
  • 59 jet-grout piles
  • 600 m3 concrete construction
  • 95.000 kg reinforcement
  • Groundwater lowering and refiltration to keep the excavation dry
  • Handling of railway safety, track possessions and power interruption



Metroselskabet I/S



Aarsleff Rail A/S together with Aarsleff


Type of contract 

Main Contract





Construction period

May 2018 - March 2020









UK / DK contact : +45 8734 3000
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