Lot 3, awarded to a consortium made up of Demathieu Bard Construction (leader) and Implenia, includes the digging of 3,814 meters of tunnel in a dense urban environment as well as civil engineering works for the construction of 4 underground stations located between 24 and 39 meters deep, and 3 ancillary works. A market that represents an investment of €331,400,000.
The tunnel will be excavated using the “Variable Density Conveyor” technique, or “variable density” tunnel boring machine concept, which is particularly recommended when faced with a variety of soil types. On the lot 3 route, this option will allow precise regulation of the confinement pressure using a real air bubble and a double pickling screw. The consortium also provides for the use of fibre-reinforced concrete segments and the recovery of 98% of the excavated earth.
Duration of works: 57 months (delivery at the end of October 2027)