Hvalfjõrôun A ‘Norwegian’ subsea road tunnel in young, basaltic rocks of Iceland

The article describes geological condidtions, the design, the feasibility and the excavation and support methods for a proposed 5,7 km long subsea tunnel under the Hvalfjord in western Iceland. Furthermore, it deals with the formal base for the private financing and operation, as well as the chosen turn-key contract type and its implications with risks and economy. Low traffic numbers call for a single tube tunnel with limited level of safety and monitoring installations. All design shall comply with Norwegian road tunnels standards. Excavation and support is expected to be heavily affected by the geology, which consists of rather thin layers of basaltic lavas from the late Tertiary, interbedded with sedimentary layers of low strength and intersected by faults and dikes in various shape and intensity.