- Client / Investor: Statensvegvesen Region vest, Askedalen 4, 6863, Leikanger, Norway, ID 971 032 081
- Design engineering: Joint venture Metrostav – Havnen Anlegg AS.
- Construction period: 06/2014 – 10/2016
- Price: EUR 10 – 50 million
Project description
Anti-avalanche measures on the road Fv.337, between Haflso and Veitastrond include dril&blast excavation of 1565 m long tunnel, road connections 550 + 330 m, avalanche walls and measures,filling of part of the lake incl. underwater blasting using Aurland method. Tunnel was excavated through granit, with strenght up to 275 MPa, max. overburden 220 m. Tunnel was excavated using dril&blast method, emulsion explosives and approx. 5 m long advances. Excavated rock was secured with rock bolts, lenght 3 – 4 m, and shotcrete with steel fibres, class E700 and E1000. Water and frost protection in the tunnel consists of 45 mm PE-foam, and 80 mm final shotcrete layer with microfibers.
Project in numbers
| Tunnel lenght: | 1 565 m |
| Tunnel profile: | T8,5 (68,77 m2) + T5,5 (45,12 m2) |
| Tunnel excavation volume: | 98 665 m3 |
| Emulsion explosives: | 270 t |
| Rockbolts: | 7 750 pcs |
| Spilling bolts: | 500 pcs |
| Shotcrete E700 or E1000: | 3885 m3 |
| Water and Frost protection (insulation): | 30 357 m2 |
| Concrete tunnel portals: | 2 pcs (117 m3 + 118,5 m3) |
| Cuts (north and south portal area): | 32 600 m3 |
| Filling of the lake, with under-water blasting: | 54 243 m3 |
| Anti-avalanche wall: | 50 4087 m3 |
| Lining of the anti-avalanche embankment: | 4 493 m2 |
| Road, asphalt constructions: | 14 464 m2 |
Extraordinary of the project
- Project was implemented in extremely difficult climatic conditions.
- In winter, works were interrupted and in certain periods was the work stopped because of high avalanche risk.
- Considering the location and limited parameters only available access road, also logistic was a great challenge.