By rosebell
The digging process of last four ventilation shafts for the Lyon-Turin base tunnel is undergoing.
In the previous month, the raise boring machine commenced excavating from the Avrieux platform as TELT says in its latest project update, whereas it is forming the 500m-deep shaft from bottom to top with a daily rate of 7.7m.
While18 excavation faces are active, work is advancing on all sites, both above and below ground. Including 19.2km of the Mont Cenis base tunnel, the total length of bored tunnels had reached 45.3km (27.7%) at the end of October.
While the responsibility of implemeting work at Saint-Jean-de-Maurienne (CO9) was up to the SNCF Réseau, they enabled the laying of welded rails on the four main and service tracks between the bridges over the Arvan and Arc rivers. Also, the tender notice for the construction of the new international station has been published. The station will be a junction on the French side between the cross-border section of the new Lyon-Turin railway line and the existing historic line.
Additionally, at the Saint-Julien-Montdenis (CO8) site, which is at four kilometres east, work continues on both the final lining of the south tube from the French entrance of the base tunnel and the conventional excavation of both tubes, whereas tunneling has also started on the 10th linking branch between the tunnels.
The station that final assembly of the back-up system elements is being completed and TBM Viviana is undergoing its break-in period is Saint-Martin-la-Porte (CO7), and this machine in order to calibrating the systems and stabilising its operation, is advancing at a rate of almost 3m per day.
The quantity of daily progress on the two conventional excavation faces heading towards Lyon is around 1.2m. Meanwhile, at the La Praz platform (CO6), excavations are progressing simultaneously from the logistics gallery. For both tubes of the base tunnel, the 1000th blast has been carried out.
Pursuing preparations for the cavern to receive the first TBM at the Villarodin-Bourget (CO5) construction site, the date of reaching to the first kilometre of galleries connecting the base tunnel to the logistics galleries was October.
As the first for the Lyon-Turin project, the Illaz excavation material processing plant has become operational at the CO11 construction site. Here some of the materials extracted from the construction sites will be sorted, treated and repurposed.
Linking the various material management sites, a 5km-long network of electric conveyor belts will be used for transporting the excavated materials, while it is due to eliminate over than 700,000 truck journeys.
Another materials processing site will be established at the CO10 site in Italy.
With the aim of extending the Berlin Wall and lower the ground level for the traditional excavation of the initial section of the Maddalena 2 tunnel, the demolition of the existing forecourt slab has been completed on the Italian side, at Chiomonte (CO3/4).
As the house for excavated material processing facilities, the Salbertrand site’s (CO10) foundation piles for the new bridge over the Dora Riparia River have been installed, and the first walls have been erected on the two abutments.
In the area of the future Interconnection Tunnel construction site (CO1), at the junction with the historic line and Bussoleno station, the four piezometers required by the Environmental Monitoring Plan for water monitoring have been installed on both banks of the Dora River.
