Skip navigation

Tunnel lrlahüll

The lrlahüll Tunnel is located entirely in white Jura (Malm). Coming from the north, it passes through Oxford limestones, followed by a lime-stone-marl stone interbedding of stratified Kimmeridge. This is followed over a distance of some 5,500 m by lime and Dolomite rocks of massive Kimmeridge, which to a great extent is highly karstified. The karst structures are very irregular both with regard to their nature and extent and range from perforated and fissured karst to filled or open negotiable cavities. In the south portal zone, the tunnel passes through tertiary clay, which is superimposed on the Kimmeridge. Over the first 2 to 3 km, the lrlahüll Tunnel is located in groundwater with the rest entirely above groundwater level. The lime and Dolomite rocks of the Kimmeridge form a huge karst groundwater aquifer. The groundwater that is present is drained and transferred into the ground from the tunnel and from 2 emergency shafts. The tunnel is headed by means of blasting and excavators with 4 main points-of-attack. During the drive, small and large karst cavities were encountered. A catalogue of measures governing the size of the encountered cavities ensures that tunnelling progresses without any difficulty Intensive investigatory measures are imperative in the base area so that the final lining can be determined. The BAB A 9 motorway embankment is encountered in the pre-cut section of the northern portal. The tunnel is driven via the wall bench method to take deformations and stability into account. In addition, a grouted pipe screen is applied. The tunnel is to be provided with 6 additional escape ways and emergency shafts with cross-sections of up to 30 m², which are designed in accordance with the valid guidelines of Fire and Catastrophe Protection. The inner shell is dimensioned with the help of the investigatory programme for the karst cavities. Once the inner shell is completed, the solid track (FF) designed for speeds of up to 300 km/h will be installed.


  • Country: Germany
  • Region: Bayern
  • Tunnel utilization: Traffic
  • Type of utilization: Main-line rail
  • Client: Deutsche Bahn AG and Planungsgesellschaft Bahnbau Deutsche Einheit GmbH
  • Contractor: Hochtief AG, Universale Bau AG
  • Main construction method: Trenchless
  • Type of excavation: Drill-and-blast
  • No. of tubes: 1
  • Tunnel total length: 7260 m
  • Cross-section: approx. 146 m²
  • Contract Volume: approx. 260 mill. DM
  • Construction start/end: 1998 till 2002
  • Opening: spring 2003