Metro Toulouse line C, Lot 3

Short description

The third metro line, Line C, will connect Colomiers and Labège in 20 minutes. Faster journeys, less congestion and pollution: this will benefit the quality of life and the environment. Implenia - Demathieu Bard Construction has been awarded the contract for one of the 4 underground lots: Lot 3, in the city center of Toulouse.

The project

Lot 3 comprises the excavation of a 3814 m long tunnel in a dense urban environment as well as civil engineering works for the construction of four underground stations at a depth of 24 to 39 m and three ventilation shafts. The construction team will use a state-of-the-art variable density TBM to excavate the tunnel. The concept of a tunnel boring machine with "variable density" is particularly recommended when different types of soil are expected during the excavation. The project is being planned and implemented using BIM.

The contract includes the detailed execution planning.


  • Implenia France (45%)
  • Implenia Switzerland (5%)
  • Demathieu Bard Construction (50%)

Services in detail

  • TBM tunneling with segmental lining
  • Earthworks
  • diaphragm walls
  • Construction work


By using segments made of fiber-reinforced concrete, theCO2 footprint of the project is kept as low as possible and the trees on the construction site are protected and preserved throughout the construction period. In addition, 98% of the excavated material is recycled.

Further information

Picture: ©Implenia

Project page for Line C from Tisseo

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