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Antwerp North-South Link (ASDAM)

The section included the driving of two single-track tunnel tubes between the Astridplatz in front of the Central Station and the Damplatz in the north of Antwerp. The contract also embraced the creation of the ramp area located there. The construction project had to be executed in the densely populated downtown area of Antwerp. The bored tunnel section is 1.23 km long. The tunnel tubes possess an external diameter of 8 m. The drive was mainly undertaken in Antwerp sand. Close to the surface there were various kinds of fills and in some cases quaternary formations with layer thicknesses varying from 2 to 4 m. The tertiary sands located underneath with shell Intrusions were in part interspersed with silt. The groundwater level was located 4 m above the tunnel. Owing to the geology that was encountered a hydro-shield with 8.27 m external diameter was selected to excavate the tunnel. Together with its three trailers the driving Installation was 60 m long and weighed a total of 860 t. The tunnel was driven from a shaft. At the end of the excavation for the first tube it was not possible to drive out the tunnelling installation into a shaft. As a result it was dismantled underground and returned through the tunnel in parts to the starting shaft. The core of the shield machine was removed and the shield skin remained in the ground. For excavating the 2nd tunnel tube a new shield skin was installed in the starting shaft, in which the machine components were installed. After assembling the shield and the trailers, the 2nd tunnel tube was driven, from the end of which the tunnelling installation once again had to be retrieved through the tunnel. Once again the shield skin remained in the ground. The monocoque tunnel lining is 35 cm thick and consists of 7 + 1 segments per ring. A ring is 1.5 m wide and the ring conicity amounts to 50 mm. A B 45 watertight concrete was applied. The rings were coupled by the cam and packet system devised by Wayss & Freytag. The two tunnel tubes were to be linked by cross-passages at 300 m intervals. These were driven by pipe jacking with an open cutting shoe protected by lowering the groundwater. Steel segments provide the connection to the tunnel tubes. On account of the inner-urban location the project was faced with a large number of technical challenges and special circumstances. From the starting shaft the drive ran entirely under buildings. The tunnel tubes had to be excavated with barely a half metre overburden. In addition there was the extremely slight horizontal clear distance of only 1.26 m between the tunnel tubes. Furthermore in the course of the excavation a number of buildings, a Metro tunnel and the Astrid Plaza Hotel had to be undertunnelled with low clearance between the lower edge of the structure and the upper edge of the tunnel.


  • Country: Belgium
  • Region: Antwerp
  • Tunnel utilization: Traffic
  • Type of utilization: Main-line rail
  • Client: NMBS CCE Strategie & Ontwikkeling (Belgian Railway), represented byTucRail N.V.
  • Consulting Engineer: CSD DE LIJN and TucRail N.V.
  • Test Engineer: SECO
  • Construction Supervisor: TucRail N.V.
  • Contractor: ASDAM JV: CFE-MGG, Belgium/Wayss & Freytag Ingenieurbau AG, NL Benelux/Dumez-GTM, France (now VInci Construction Grands Projets)/Jan de NuI, Belgium/Van Laere, Belgium/Smet Tunnelling, Belgium
  • Main construction method: Trenchless
  • Type of excavation: Shield machine (SM)
  • No. of tubes: 2
  • Tunnel total length: 2,456 m
  • Cross-section: 53.7 m² (bored diameter)
  • Contract Volume: 81 mill. Euro
  • Construction start/end: May 2001 till March 2005
  • Opening: April 2006