Wehrhahn Line Düsseldorf Contract Section 1, Core Section

The regional capital of Düsseldorf is producing the so-called core section, the Wehrhahn Line, in the form of an underground urban railway route. Thanks to the new twin track underground route, devised to replace five tram lines on the surface, public commuter transportation (ÖPNV) will take a great stride forward. The new 3.5 km long urban railway route with 6 underground stations and 2 stations on the surface runs underground from the Bilk S-Bahnhof to the Wehrhahn S-Bahnhof and by and large follows the Elisabeth/ Kasernenstraße and Schadowstraße/ Am Wehrhahn road alignments. The new tunnel joins up with a section of tunnel (below the track level in use today - the Heinrich-Heine-Allee Station's so-called C Level) that is approx. 152 m long, built at the same time as the station. The tunnel is produced by a shield drive so that there is as little as possible impairment caused on the surface for the route sections. The stations and the individual route sections are produced by the top cover method as well as by cut-and-cover protected by excavation pit covers. Extensive accompanying jobs have to be carried out on roads, utility lines and sewers that are logistically tied up with the tunnelling work. Minimising nuisance to the environment and the surrounding facilities enjoys highest priority. The shield drive for the 1,298 and 955 m long segmental tubes is marked by the following characteristics:

Hydro-shield with 9.49 m excavated diameter in quaternary sands, gravels and Rhine Terrace blocks with water pressures of up to 2 bar and overburdens of up to 15 m
Monocoque segmental lining consisting of 1.50 m long rings with cam/ pocket coupling and EPDM sea ling profile (8.30 m inner shell diameter, 9.20 m externaldiameter,45 cm thick, 7+1)
Shallow overburdens at the starting and target pits, shield arrival in flooded diaphragm wall excavation (2x)
Passage through 4 stations prior to their excavation with subsequent removal of the segmental tube
Compensation grouting from ancillary shafts in order to control settlements at critical buildings.

Country: Germany
Region: Düsseldorf, North Rhine Westphalia
Tunnel utilization: Traffic
Type of utilization: Underground, urban and rapid transit
Client: City of Düsseldorf, Office for Transport Management
Consulting Engineer: Ingenieurgemeinschaft Wehrhahn-Linie: Schüßler-Plan/ Zerna Ingenieure/Spiekermann GmbH/ Ingenieurbüro Wendt
Contractor: Bilfinger Berger AG
Main construction method: Open/trenchless
Type of excavation: Shield machine (SM)
Lining: Reinforced concrete segments
No. of tubes: 1
Tunnel total length: 1298 + 955 m
Contract Volume: 297 mill. Euro net. (roughwork Lot 1)
Construction start/end: 2007 till 2015