The Weinberg tunnel in Zurich

To improve the service and increase rail passenger capacity in Switzerland's most important economic region, the Swiss Federal Railways and the Canton of Zurich have decided to build a new double-track rail link beneath the city centre. The key components of this so-called Durchmesserlinie (Diameter line) will be the Weinberg tunnel and the new underground station beneath Loewenstrasse. Almost all of this approx. 5 km long tunnel will be driven by an 11 m diameter mixed-shield tunnel boring machine (TBM); 4300 m through sedimentary rock (molasse formations) and 210 m through water-bearing glacial, and river and lake deposits. Special construction methods are required where the tunnel widens to pass under the south wing of Zurich's 150-year old main station building, with its extensive underground shopping area. Several important tunnels of comparable cross-section have in recent years been excavated in similar rock formations of the Zurich region. All these cases showed that TBM excavation, with immediate placing of pre-cast lining segments followed by in situ inner concrete lining, was the most economic solution. The new Weinberg tunnel will also be driven by TBM. On completion of the tunnel through the molasse formations, the machine will be modified for hydro (slurry)-shield operation for the remaining excavation in the loose glacial and lake and river deposits. Conversion of the TBM will have to be done in the transition zone from molasse to moraine material. The section excavated with the hydro shield passes beneath the River Limmat and one of Zurich's most complex and busiest traffic intersections. To avoid any settlement of the very sensitive tram tracks and points, it is proposed to construct, prior to excavation of the tunnel, a pipe canopy directly above the tunnel. This will consist of eight horizontal concrete pipes, each of about 1.90 m outer diameter, which will be jacked from a shaft, and will then be filled with concrete. The length of the canopy will be about 105 m. One of the most challenging sections of the railway tunnel is the construction beneath the south wing of the existing main railway station. For geometric reasons it is not possible to construct the tunnel with a circular cross-section and by normal tunnelling methods, as the track levels in the new station have to be as high as possible. The basis of the concept is a pre-stressed supporting structure to be constructed in stages beneath the south wing from a system of small-diameter galleries. From two such longitudinal galleries the outer diaphragm walls will be constructed to serve not only as supports for the beams of the transverse supporting structure but also to enclose the construction area below it. To form the supporting structure, cross beams will be concreted side by side in adjacent transverse galleries. As soon as these have been completed, the tunnel will be excavated below it and the main internal concrete structures can be constructed. At presently, the project is in the design stage. After issue of the required permits, construction of the tunnel will start in 2007 and last until 2013. (A). "Reprinted with permission from Elsevier". For the covering abstract see ITRD E124500.

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  • Authors:
    • FAESSLER, G
    • HESSLER, N
    • MATTER, J
  • Publication Date: 2004-7

Language

  • English

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Filing Info

  • Accession Number: 01011537
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD
  • Created Date: Dec 19 2005 3:16PM