Infrastructure branch Making all the difference

The Underground Division: years of in-depth experience

Our underground projects have been one of Eiffage Génie Civil's specialist fields for many years. They are technical and often complex, but always unique and subject to stringent preparatory phases.


    Our teams' technical skill and experience on all types of ground is widely recognized.


    We are proud of our successful road, rail and industrial tunnel projects.


    We are expert in all the current tunnel-boring techniques.

Underground building techniques

At Eiffage Génie Civil we contribute our expertise in building new structures, rehabilitation, loading gauge provision and safety solutions to all types of project, including road, rail and industrial tunnels, sewers and hydraulic facilities (with their tunnels, shafts, chimneys and caverns).

We offer a complete range of techniques including TBM boring and blasting by conventional methods or with road-headers, together with unique experience on all types of firm and soft ground and bedrock.

Specialist teams

Our Underground Division comprises a number of specialist teams of engineers, technicians, geotechnicians, TBM operators and blasters who manage the specific risks associated with this type of operation, adapting their methods to suit both urban and natural environments.

Social, societal and environmental responsibility

The Underground Division is aware of its social and societal responsibility, playing a key role in training and integrating priority target groups with enthusiasm, and managing daily relations with local residents and coordination with concession holders and other communal services.

Where the environment is concerned, the Underground Division deploys all its skill and experience to integrate discreetly into the town, using proven measures for works and transport organization, choice of materials,  noise studies and traffic modelling.

Underground works training

In-service training sessions are organized on a regular basis, enabling workmen joining the division to obtain the necessary qualifications, such as the Caces safe driving aptitude certificate or the CPT firearms certificate for staff required to handle explosives.


  • Violay Tunnel - A89 Motorway
    Violay Tunnel - A89 Motorway

    Unidirectional 3,900 m twin-tube motorway tunnel on the A89 between Balbigny and La Tour-de-Salvagny.

    Excavation : 663,000 m³
    Shotcrete : 66,620 m³
    Concrete surface coating : 265,000 m³
    Timeline : 38 months
    Commissioned : 2013

  • Inelfe

    Power interconnection between France and Spain

    Length : 8,250 m
    Excavated section : 14.73 m²
    Excavation : 122,000 m3
    6,720 1.20 m arch segment rings
    Concrete : 5,000 m³
    Filling mortar : 11,200 m³
    Timeline : 38 months
    Commissioned : 2015


  • Source substation - Monaco
    Source substation - Monaco

    We built a third source substation in the rock mass to increase power distribution.
    Underground structure built with conventional blasting methods, involving manual or mechanical digging.
    Excavation work by blasting : 28,000 m3 with environmental restrictions requiring sophisticated technical methods.
    Timeline : 29 months
    Commissioned : 2015

  • Lyon-Turin Euralpine Tunnel
    Lyon-Turin Euralpine Tunnel

    We developed the foot of the existing Saint Martin la Porte decline, as a preliminary to the start of tunnelling.
    Timeline: 8 years (for the project underway)

  • Paris Metro - Line 14
    Paris Metro - Line 14

    Extension of Paris Metro Line 14 between the rear part of Saint Lazare Station and the future Clichy Saint Ouen station.

    We tunnelled 3.6 km by TBM (8 m of interior diameter) and built Pont Cardinet and Porte de Clichy stations with diaphragm walls. Dimensions : 120 m long, 20 m wide, 20 to 60 m deep and 1.80 m thick.
    Project underway.

  • Prado Sud Tunnel - Marseille
    Prado Sud Tunnel - Marseille

    Concession, construction and operation of an underground road structure comprising a small-sized toll tunnel on two levels, one for each traffic direction (two lanes per direction).

    Height: 3.20 m
    Length : 1,500 m. Built using cut and cover techniques, with the help of diaphragm walls, respecting the existing lanes’ right of way.
    Site located in a built-up urban area.
    Timeline : 5 years
    Commissioned : 2013

  • Western tunnel, Monaco
    Western tunnel, Monaco

    Road tunnel with a maximum slope gradient of 6%.
    Length : 1,677 m
    Cross-section 90 m²
    Excavation : 180,000 m3
    Timeline : 5 ans
    Commissioned : 2016

See also