Nordic sub sea tunnel projects

The paper reviews the experience from Nordic sub sea tunnel benchmark projects, with main emphasis on sub sea road tunnels excavated in bedrock. More than 25 such tunnels have been built in the Nordic countries, representing a total length of more than 100 km, and with the majority of the projects located in Norway. The completed projects include tunnels with length up to 7.9 km and depth below the sea level down to 264 m. All these tunnels have been excavated by drill and blast. Important issues concerning investigation, planning, design and construction are described, and important lessons learned from these projects are discussed. Finally, plans for potential future sub sea tunnel projects are presented, representing tunnel lengths of up to 24 km and depths below sea level down to 400 m.