Skip navigation

Fürth Underground Railway, Line 1, Contract Section 3.1.1, Klinikum Station and Tunnel Sections

Contract section 3.1.1 of Underground railway line 1 represents a continuation of the existing 3.3 km long metro system of the City of Fürth towards the west - starting from the Stadthalle Station. Along the entire 1,313 m long route section, 2 single-track tunnel tubes with an excavated area of 35 m² as well as a 379 m long twin-track tube with an excavated area of 89 m² were produced by mining means. The starting shaft at the Klinikum Station as well as the access shaft at the Stadthalle Underground Station bordering on contract section 2.1 was created by cut-and-cover. The subsoil around the tunnel tubes is divided up into 2 very different zones. The bulk of the new section is located in trias sandstone keuper. Geologically speaking, young sand and sand-gravel deposits (quaternary) were encountered around the eastern access shaft. The production of the Klinikum Underground Station as well as undercutting a number of historic buildings where the tunnel starts in the east represented the most challenging features in technical terms. The Klinikum Underground station was built over a distance of some 60 m protected by a pipe umbrella cover consisting of steel pipes 1,420 mm in diameter and a wall thickness of 25 mm. The minimum gap between the steel pipes and the foundations of the buildings amounted to only 30 cm. An open cowl shield with excavator arm was employed for tunnelling, which was followed by the installation of the steel pipes. The quaternary sands and gravels above the excavated cross-section had to be frozen using a brine solution over a length of 60 m so that the historic buildings located where the tunnel begins in the east could be passed under. In order to create this frozen zone with a volume of 2,500 m³, 60 m long controlled horizontal drillings were undertaken through the excavation pit wall to counter pressing groundwater. The single and twin tunnel tubes were driven using the NATM with a short advance crown by a roadheader. After the excavation was complete, the tunnel tubes were lined with a watertight B 35 in situ concrete shell. The mass-spring system was chosen for the track to avoid vibrations caused by travelling rolling stock.

 

  • Country: Germany
  • Region: Bavaria
  • Tunnel utilization: Traffic
  • Type of utilization: Underground, urban and rapid transit
  • Client: infra fürth verkehr gmbh
  • Consulting Engineer: Design: City of Nuremberg, Foundation Engineering Office/Underground Railway Construction; Execution: Köhler und Seitz
  • Contractor: Max Bögl Bauunternehmung GmbH & Co. KG, Bilfinger Berg er AG, Ed. Züblin AG
  • Main construction method: Trenchless
  • Type of excavation: Roadheader
  • Lining: In-situ-concrete
  • No. of tubes: 1
  • Tunnel total length: Length of section 1,313 m, 1,560 m of single-track tubes, 120 m of twin-track tubes, 260 m enlargement cross-section
  • Cross-section: 35 to 89 m²
  • Contract Volume: € 35 million net
  • Construction start/end: August 2000 to March 2004