In 2013, NCC completed the construction of a tunnel project on the E6 expressway in Trondheim city center. The contract had a value of 554 MNOK.
NCC was awarded the project to construct a complicated tunnel in Trondheim city center. The project was conducted in close cooperation with the Norwegian Public Roads Administration, NCC's own advisors and the Norwegian Directorate of Public Roads applying an approach focused on successfully carrying out a project rather than solving conflicts. NCC held its own series of meeting on the theme of geotechnics to keep the focus of the project on implementation and quality.
NCC's contract was for a 500 m road with a 350 m concrete tunnel. The area had a high proportion of quicksand that had to be stabilized using extensive piling and lime cement stabilization methods before excavation work could begin. The concrete tunnel was built in a 20 m deep construction pit, through quicksand in a city area that included both protected buildings and high volumes of transit traffic on the road (E6 expressway), footpaths and railways. The construction pit was subject to particularly strict requirements on how rigid and watertight it was.
The obstacles of a constricted construction site, polluted soil and many phases of traffic diversions made this one of the most challenging road projects in Norway to date. The project was part of the E6 expressway Trondheim to Stjørdal, under which much of the transit traffic in Trondheim was to be routed down into tunnels beneath the city, thus improving the urban and living environment.
The project had an intense focus on environment, health and safety (EHS) work, since the construction pit was so constricted and many activities were taking place simultaneously. Safe work analyses and safety rounds were major focus areas of both developer and contractor.
NCC’s method proposals involve several elements not previously seen in Norway. These include:
The softsoil tunnel was named “Civil Engineering Project of the Year 2014” and the jury’s citation was as follows: “The project serves as a prime example through its excellent organization and willingness to use new technical solutions in its implementation.”