Metro Nuremberg U3, North West BA, 1.3
The Nuremberg Metro is one of the more recent Underground systems in Germany being opened in 1972. Since 2008 it has become Germany's first with a fully automatic driverless Metro line. Construction section 1.3 for the U3 is roughly 1.1 km long and includes two stations, built by cut-and-cover, as well as 1 and 2-track tunnel sect ions produced by mining means. The existing U 3 Underground line is being extended by a section of route under extremely constricted inner-urban traffic conditions. The stations are built by cut-and-cover with reinforced bore pile walls and back-anchoring. The concrete structures are produced under ancillary bridge covering with variable openings in order to maintain road traffic - without triggering any real cause for complaint by the public. The 1 and 2-track structures for the route with enlargement areas are driven by mining means without unduly harming the rock using a roadheader. The excavation is secured by means of a reinforced shotcrete outer shell. Then a watertight inner shell is produced. The driving operations are mainly undertaken in crumbly to hard Blasen sandstone of the Keuper formation. The rock can be classified as stable. There is no accessing groundwater worth mentioning. In the mined section shortly behind a start-up wall there is an individual foundation subjected to great load only a few cm above the crown drive. To provide support a drive with advance lanes in conjunction with underpinning the foundation with reinforced concrete beams was selected. The critical points of the building were collated by means of a system of sensors. If certain warning values were exceeded an alarm was at once sent to the site management automatically. The settlements resulting from the driving operations brought about a total settlement of a few mm for the individual foundation and underpinning was concluded without any damage being caused. A mass-spring system is being built in the Underground facility to protect it against noise. It consists of reinforced concrete track bearing plates in individual lengths of up to 22 m, which are 63 cm thick. The plates are concreted on a separating layer on the tunnel base, then raised by means of hydraulic jacks and set on elastic spring layers installed underneath.
- Country: Germany
- Region: Bavaria
- Tunnel utilization: Traffic
- Type of utilization: Metro
- Client: City of Nuremberg
- Consulting Engineer: Ingenieurgemeinschaft U3 Nürnberg NW BA 1.3
- Construction monitoring: Nuremberg Metro Construction Office
- Contractor: Hochtief Construction AG, BK Infrastruktur GmbH
- Main construction method: Open/trenchless
- Type of excavation: Top cover construction method/drill-and-blast
- Lining: Concrete formwork/shotcrete
- No. of tubes: 1
- Tunnel total length: open construction method: 243 m (Kaulbachplatz Station), 142 m (Friedrich-Ebert-Platz Station), 36 m (Bielingplatz); miningmeans: 938 m (single-track tubes), 192 m (twin-track tubes)
- Cross-section: 35 m² (single-track tubes), 65 m² (twin-track tubes)
- Contract Volume: approx. 46 mill. Euro (gross)
- Construction start/end: 2007 till 2010