CFF Line 224 / Lot 3 / Project No. 1148146
Neuchâtel – La Chaux-de-Fonds (CH)
Minimal renovation of the tunnels des Loges and du Mont-Sagne. Renewal of the tunnel Combe-Convers.
Construction of the Grandes-Crosettes coupling station.

Main quantities: LOG MTS CCO Total
Excav. MUV: 23’000m³ 2’510m³ 10’200m³ 35’710m³
Blade cuts: 2’500m² 4’000m²
Shocrete: 16’700m³ 720m³ 2’880m³ 20’300m³
Lattice girder: 50to 8to 55to 113to
Waterproofing: 7’500m² 790m² 1’720m² 10’010m²

Tunnel des Loges LOG, 3'259m:

• Collecting and sealing water inlets from the mountain.
• Demolishing of the existing masonry support; Section

enlargement; Construction of a new shotcrete vault.

• Diamond blade cutting of existing rock for reprofiling
• Excavation and support works for 6 new logistics niches.
• Replacement of the cable channel and floor drain.
• Refurbishments works at the portals.

Tunnel du Mont-Sagne MTS, 1'352m:

• Collecting and sealing water inlets from the mountain.
• Demolishing of the existing masonry support; Section

enlargement; Construction of a new shotcrete vault.

• Diamond blade cutting of existion rock for reprofiling
• Replacement of the cable channel and floor drain.
• Refurbishments works at the portals.

Tunnel de Combe-Convers CCO, 254m:

• Collecting and sealing water inlets from the mountain.
• Excavation and support works for 5 new escape

niches.

• Demolishing of the existing masonry support; Section

enlargement; Construction of a new shotcrete vault.

• Replacement of the cable channel and floor drain.
• Refurbishments works at the portals.

The line crosses the Jura rocky chain. It is the result of a folding of the Mesozoic marl-limestone series. The limestone sections are fractured and karstic and are potential aquifers.