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Einhorn tunnel, B29, Schwäbisch Gmünd

As part of the development of the B 29 it is essential to build the Schwäbisch Gmünd Tunnel to provide a bypass for the town of Schwäbisch Gemünd on account of the topographical conditions. The tunnel is altogether 2,530 m long including the related trough sect ions. The tunnel is divided up in to the following sect ions from west to east: following a 215 m long t rough section there is a 230 m long cut -and-cover section. This links up with a 1,687 m long section driven by mining means in the central part of the tunnel. In the east the tunnel ends up with a 315 m long section produced by cut-and-cover as well as a connecting 90 m long trough section. The prerequisite for tunnelling in the east is the relocation of the Rems in a new river structure. The evacuation tunnel is linked with the road tunnel by means of 6 escapeways, one of which is accessible to traffic to a limited extent. In a second development stage the production of a second tube along the route occupied by the evacuation tunnel and then operation as directional traffic tunnels is planned. Four lanes have been foreseen for the trough sections and the cut-and-cover tunnel sections du ring the first development phase, which are joined to form 2 lanes. The underground conditions are characterised by quaternary deposits forming Rems and Lindenfirst rock, which belongs to middle keuper. At stake is so-called coloured marl consisting of intermittent beds of solid clay and sandstone layers. The groundwater level within the quaternary deposits as well as in the weathered zone above the prevailing rock corresponds with the water level of the Rems in the valley floodland plains. The entire tunnel to be driven by mining means will lie below the underground water level in its final state. On account of the hydrogeological conditions the tunnel will receive an approximately circular cross-section in order to provide the clearance profile of the standard cross-section, RQ 10.5 T, which possesses a carriageway width of altogether 7.5 m and two 1 m wide emergency footpaths. An intermediate ceiling is to be installed over a length of 1.734 m, which has exhaust flaps set up at 60 m gaps, for removing the tunnel waste air as well as smoke gases in the event of fire. An exhaust air centre with ventilation is to be set up in the middle of the tunnel for removing waste air.


  • Country: Germany
  • Region: Swabian Alb/Baden-Württemberg
  • Tunnel utilization: Traffic
  • Type of utilization: Road Tunnel
  • Client: Federal Republic of Germany/Land of Baden-Württemberg/Regierungspräsidium Stuttgart
  • Consulting Engineer: BUNG Ingenieure AG, Heidelberg; Müller+Hereth GmbH, Karlsruhe
  • Test engineer: Prof. Dr.-Ing. Dieter Kirschke, Ettlingen
  • Contractor: Ed. Züblin AG, Baresel GmbH/G. Hinteregger & Söhne GmbH, Östu Stettin GmbH
  • Main construction method: Trenchless
  • Type of excavation: Drill-and-blast
  • Lining: Shotcrete
  • No. of tubes: 1 (+ rescue passage)
  • Tunnel total length: 2,530 m
  • Cross-section: 105- 220 m²
  • Contract Volume: 190 mill. Euro (roughwork), 16 mill. Euro (operating technology)
  • Construction start/end: 2008-2012 (62 months)
  • Opening: December 2012