French metro progress in Rennes and Paris 08 Mar 2018

Successful construction works in France are advancing Metro system extensions in Rennes and Paris.

In Rennes, TBM tunnelling for the city’s Line B Metro Lot 1 contract came to a conclusion at the end of February 2018 when a 9.41m diameter Herrenknecht TBM completing its task after 38 months of multiple breakthroughs along the 8.56km long route.

Working for a construction JV lead by Vinci, through its subsidiary Dodin Campenon Bernard, and including GTM Ouest, Botte Fondations, Spie Batignolles TPCI, Spie Fondations and Legendre Genie Civil, the EPB machine was launched at the start of 2015 broke through and was pull-through nine station boxes and four ventilation shafts to create the new single-tube double-track underground line.

Geology along the route comprised soft ground, slate and sandstone that proved to be tougher than predicted. The TBM, with a cutterhead power of 3,200kW and a torque of 25,790 kNm, was operated with a reduced angle of opening at the cutting wheel and had an installed stone crusher.

All supply logistics to the advancing machine were handled from the launch shaft and along a winding alignment with curves of as tight as 180m radius. The 9.1m o.d. rings of 400mm thick x 1.3m and 2m wide, comprised seven segments and were cast in moulds supplied by CBE.

Following dismantling of the machine, the remaining civil engineering work for the route and its total 15 metro stations is due to be completed for commissioning of the automated train services in 2020.

Network of metro lines and extensions for Paris Metro

As running tunnel excavation was finalised in Rennes, the Vinci and Spie Batignolles lead JV recorded a success in the French capital with award of the GC02 Lot on Line 14 South of the Grand Paris Express. Valued at almost €400 million, tunnelling on the contract calls for 4.6km of EPB excavation from the launch shaft at Jean Prouve and the future station at Maison Blanche Paris XIII. The 72-month contract also includes constructing five ventilation and emergency shafts, and the Kremlin Bicetre Hopital station.

Line 14 South will have a number of Metro, RER and tram system interchanges, including links with the new Lines 15 South and 18 of the Grand Paris Express and is being built as a a key link to the Orly Airport, for when Paris hosts the Olympic Games in 2024.

The new contract adds the Lots T3C and T2D contracts that the JV is progressing on the new Line 15 South of the Grand Paris Express project.