The Vaðlaheiði Road Tunnel (Vaðlaheiðargöng) completed a ring road around Iceland, connecting the towns of Akureyri and Fnjöskardalur. The 9.5m diameter single-tube tunnel stretches 7.2km and has a cross section of 66m². During construction, a heavy ingress of geothermal water with temperatures reaching up to 65°C brought excavation to a halt. To overcome this issue, different solutions were required at varying chainages throughout the tunnel.
Vaðlaheið Road Tunnel, Akureyri – Iceland
The Vaðlaheiði Road Tunnel (Vaðlaheiðargöng) completed a ring road around Iceland, connecting the towns of Akureyri and Fnjöskardalur. The 9.5m diameter single-tube tunnel stretches 7.2km and has a cross section…
Sector / Application
Overview
Solution
At chainage 1870-1970, invert injection was used to reduce water ingress, air temperature and humidity. Four invert umbrellas comprising 12 boreholes, each 12m deep, were drilled and injected using CarboPur WX and accelerators, while CarboPur WF with additives was used in the most challenging conditions.Following the invert injection works, additional boreholes were drilled into the tunnel wall to seal the water source. This reduced water inflow by 80%, from approximately 600 l/sec to 120 l/sec, allowing the remaining water to be managed via a drainage system.At chainage 3405, three 18m deep injection umbrellas were drilled ahead of the face at an angle of 15° outside the tunnel profile. CarboPur WX and accelerators were injected to achieve a rapid set before further drilling and injection up to 25m into the face using the SK90 Resin Injection system and hydraulic packers. The water ingress was eliminated.Following an 8–9 month delay, the successful treatment enabled excavation to resume, with both client and contractor expressing their satisfaction with the results achieved by Minova
