Skip navigation

Metro Berlin, Line U55, Brandenburg Gate Underground Railway Station

As part of the scheme to construct transportation facilities for the new government district in Berlin's central area, approx. 1,500 m of tunnel was produced in carcass state from 1996 to 2000, close to the Reichstag parallel to the north-south mainline rail tunnels and the B 96 road tunnel. This tunnel, produced on behalf of the Senate Administration for Building and Housing, is intended for the extension of the U 5 from Alexanderplatz to the future Main Station. The roughwork for the "Main Station" and "Reichstag" stations was also included. The latest plans indicate that the link with the existing Underground network at Alexanderplatz will be undertaken in 2012 at the earliest. ln order to make use of what has already been constructed as soon as possible, a third station, the "Brandenburger Tor" Station, with connections to the North-South S-Bahn lines is to be built in advance. This station is to have an approx. 11 m wide central platform with a useful length of 115 m. It will be roughly 17 m below street level. Once completed, there will be stairways and smoke removal shafts at both ends of the station. The site is located in the most prominent part of Berlin, directly to the east of the Pariser Platz just in front of the Adlon Hotel and other top-class abutters. The access and transfer structures are located beneath the central promenade of "Unter der Linden" Straße. The Wilhelmstraße together with supply and disposal lines that are to be found underneath is to be undercut over a length of some 20m. The centre of Berlin with "Unter der Linden" Straße and the Pariser Platz are located in the Berlin ice marginal valley. The subsoil is characterised by glacial sediments with thick layers, quaternary sand as well as sand and gravel mixtures, which have thin layers of fills superimposed on top of them. ln some cases, the deeper lying sand layers are of glacial origin. At depths in excess of 40 m, the sand layers are superimposed on glacial marl or brown coal clays and silts. ln the sand layers, there are occasional boulders (rocks), especially in the former glacial marl basis zone. These thick sand layers form a comprehensive groundwater stratum with only a slight incline and low flow speed. The groundwater is to be found up to roughly 3 m beneath the ground surface. In order to minimise nuisance to local residents in this extremely busy tourist district, the station building has largely to be produced by mining means in compliance with the plan approval resolution. A tight, multi-reinforced and covered diaphragm wall excavation pit measuring 25 x 20m had to be produced as the starting shaft for the drive in the vicinity of the access structure. A back-anchored fairly deep-lying jet grouted base slab is used to secure the excavation horizontally. The diaphragm walls excavated by grabs are roughly 25 m deep. As lowering of the groundwater table is not feasible both for ecological reasons as well as to protect historical buildings, it was decided to drive the station area by mining means protected by frozen zones. The drive is undertaken in part-sections, with the frozen zones fulfilling sealing as well as temporary bearing functions around each part-section. On account of the long column lengths and the required positional accuracy, the freezing lines have to be set in the soil by means of 30 micro-tunnels each 1.5 m in diameter. Brine is used to produce and retain the frozen zone. For the first time in Germany, a GFK reinforcement is being installed in the area where the 30 micro-tunnels pass through the diaphragm walls. As there is no general official approval for the GFK reinforcement, the Technical Supervisory Authority was requested to provide a permit in individual cases. It is intended to have part of the Pariser Platz construction measure ready for the 2006 World Cup.


  • Country: Germany
  • Region: Berlin
  • Tunnel utilization: Traffic
  • Type of utilization: Underground, urban and rapid transit
  • Client: Berliner Verkehrs Betriebe (BVG)
  • Consulting Engineer: Zerna, Köpper & Partner, PSP Beratende Ingenieure, CDM, DMT, Krebs und Kiefer, Seidl & Partner
  • Examination: Prof. Duddek und Partner GmbH
  • Contractor: Hochtief Construction AG, Max Bögl Bauunternehmung GmbH & Co. KG
  • Main construction method: Trenchless
  • Type of excavation: Excavator
  • Lining: In-situ-concrete
  • No. of tubes: 1
  • Tunnel total length: approx. 145 m (after completion)
  • Cross-section: 186 m² excavated cross-section in the platform area
  • Contract Volume: approx. € 33 million (after completion)
  • Construction start/end: 2004 to 2007
  • Opening: 2007