Lining designs for Norwegian road tunnels: Proc. World Tunnelling Congress '99: Challenges for the 21st Century

Abstract

To overcome communication difficulties in the Norwegian landscape of mountains and fjords, 850 road tunnels have been built. Half of these tunnels have a traffic volume less than 1000 ADT, as they are primarily links to scattered settlements. Panels made of frost insulated, aluminium corrugated sheets and PE-foam linings have been in extensive use. Recently, shotcrete/PE foam linings, PVC-coated polyester fabric linings and prefabricated concrete elements of special designs have been introduced. Applying seperate methods to accomplish the rock support and the water/frost protection is one of the basic principles of the NPRA road tunnel design. It has been found that this yields an optimum between performance and economy.