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The best underground connections.

Tunnelling is one of the most demanding disciplines in construction engineering and also happens to be one of PORR’s core competencies. Underground construction requires specialist expertise, innovation, flexibility, and a talent for technological solutions. In addition to the priority of conserving the environment and resources, key factors for PORR include occupational health and safety and quality. As a reliable partner we have a strong track record with our technical expertise in every common tunnelling method (gripper TBM, open shield, EPB and hydro shield) as well as with cross sections from 6 to 13 metres.

Our service range stretches from building traffic tunnels such as road, metro and railway tunnels, along with infrastructure facilities, right through to the supply of drinking water. District heating pipes, wastewater pipes and cable ducts along with other underground construction such as galleries, shafts, caverns or hydraulic engineering complete the range.

We employ the following technologies:

  • Conventional tunnelling (cyclical) using the New Austrian Tunnelling Method (NATM) 
  • Mechanical (continuous) tunnelling with tunnel boring machines (TBMs) with diameters of 2.5m to more than 13m
    • Tunnelling with a hard-rock TBM (gripper machine) with subsequent inner lining of in-situ concrete
    • Tunnelling with shield TBM with simultaneous single-layer segmental lining or double-layer with segments and in-situ concrete lining
    • Hydro-shield tunnelling: tunnelling with a slurry-supported working face, segmental lining
    • Earth-pressure-balance shields (EPB) with face support by balancing the earth pressure, segmental lining
  • Multimode tunnelling with alternating operating modes (EPB/slurry-supported/open), segmental lining
  • Mechanical tunnelling with tube extrusion technology with partial or full section methods, using a slurry-supported working face if necessary, tube diameters from 1.5m to more than 4m
Extension of the U5 Europaviertel metro line Frankfurt a. M.
For reference
Stuttgart 21
Lot 1A and Lot 1B
For reference
Untertürkheimer Kurve railway tunnel for Stuttgart 21
For reference
Finne Tunnel Herrengosserstedt
For reference
Horchheimer Tunnel Koblenz
You can find more projects here
To the projects

Contact partner.

PORR BAU GMBH Dipl. oec. Hüseyin Gürbüz Head of Tunnelling Department
PORR GMBH & CO. KGAA Dr. Thorsten Weiner Head of Tunnelling Department
PORR BAU GMBH Mag. Alexander Soudi Division Manager Tunnelling


Ensuring quality requirements is a top priority at PORR. This is also evidenced by our certificates and approvals. In order to always be up to date, our certificates and approvals are reviewed and updated on a regular basis through external audits and independent certification companies.

In addition, independent companies, such as Deutsche Bahn AG, confirm our skills and actions through prequalifications and special recognition.

All certificates, approvals and memberships can be found here: