Fv. 714 Stokkhaugen – Sundan: Åstfjordkryssinga

  • Client / Design: Statens vegvesen, Region Midt, Julsundvegen 9, 6412 Molde
  • Contractor: Joint venture Metrostav – Bertelsen & Garpestad
  • Contractual time period: 1/2018 – 10/2020
  • Contractual price: 800.992.632 NOK excluding VAT, 80,1 million EUR (Approx.)

Project Description

The project is a part of a larger initiative focused on increasing the safety and capacity of the Fv.714 road. The road connects the Norwegian mainland with Hitra island. The project consists of 5,6 km of new road construction which includes a bridge crossing the Åstfjord with the length of 735 m and two tunnels with profile T 9,5 – Slørdal tunnel (2.650 m), Mjønes tunnel (770 m). It also connects to the local roads, bus stops and parking lots. The contract is for complete delivery, including electrical installations. Metrostav was responsible for the main parts of the bridge, mainly foundations, reinforced concrete and steel structures. Additionally, Metrostav also performed the excavation and support of both tunnels and reinforced concrete tunnel portals.

Project data

Section legth: 5,6 km
Tunnels: 2 pcs (2650 m + 770 m)
Tunnel portals: 4 pcs (2×44 m, 2×29 m)
Bridge: 735 m
Tunnel profile: T9,5 (80 m2)
Blasting in tunnels: 273.000 m3
Bolts: 13.500 pcs
Concrete for structures: 17.840 m3
Reinforcement: 2.785 t
Steel structures: 2.660 t
Piles, Micropiles: 1.640 m, 210 m

Challenges / Specifics of the project

  • Reinforcement, formwork and concreting 12 m under the sea level
  • Concreting of the wells using sliding formwork on a submersible barge and submerging of the wells to the desired location and their filling
  • Reinforcement and concreting of large diameter piles with length up to 50 m rammed into the seabed
  • Installation of steel structure to the pile heads with the help of divers
  • Concreting of the pillar feet at the sea level using precast lost formwork installed by ship and mobile cranes
  • Concreting of the bridge pillars of the height up to 40 m using sliding formwork in gruelling climatic conditions and challenging logistics
  • Manufacturing and transport of the steel structure with section up to 140 m long and weighing up to 430 t.
  • Precise placement of the steel structure sections to the pillars using a ship crane with capacity 800 t and a crawler crane with capacity 600 t
  • Concreting of the bridge deck using moving formwork in a section of 25 m above the sea

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