An expert group in the Statens vegvesen (the Norwegian Public Roads Administration) thinks it is possible to save about NOK 5.4 billion at the building tunnels in a simpler but adequate manner, in 20 national roads.

The expert group has looked at the tunnels on the 20 road projects that are on the priority list for the Norwegian Public Roads Administration. This is a project that costs more than one billion kroner. 166 kilometers of new tunnel will be built on the stretches. Several of the tunnels gets two tunnel runs, so that it will be built 233 kilometers of tunnel runs.

The Statens vegvesen thinks it is possible to build tunnels on a simpler, yet satisfactory, way. In addition, there will be savings potential for tunnels that will be rehabilitated and tunnel projects below NOK 1 billion. The proposals can also benefit from the county municipalities and Nye Veier AS.

Several of the measures will also make it easier to operate and maintain the tunnels. It is important. The Road Administration currently spends NOK 700 million on operations and maintenance of tunnels in Norway.

38 Action Points

The working group with experienced tunnel people from all over the country has assessed 38 different measures.

These are some of the measures with the greatest economic effect:
• Reduce thickness on concrete elements.
• narrower road shoulder for tunnels with moderate traffic
• Open for the use of spray concrete over PE foam/membrane on tunnels with a relatively highvtraffic
• consider new solutions for fire extinguishing

Less concrete and steel
The tunnel group has also assessed how the modernization of Norwegian tunnel construction will turn out to the climate account. There is especially a measure that cuts the emissions of CO2 sharply: By reducing the thickness of the concrete elements from 15 to 12 centimeters it is possible to use a reinforcement net in the city for two. It provides more concrete between the reinforcing iron and the rock wall on one side and against the traffic on the other. Smaller concrete and reinforcing bars also provide less transport

- This is how you get more than strong enough concrete wall. Some people also use stainless steel, increasing the life of the tunnel walls from 50 to 100 years. This is how we can spend less money, while cutting CO2 emissions with 65,000 tonnes of CO2, says project manager Marius Slinde.

He thinks regulations and practice make Norwegian tunnels unnecessary expensive.

- You can build many kilometers with a new road for NOK 5.4 billion, says Slinde.

Five of the measures can be implemented without changing the regulations for the construction of tunnels. Seven of the measures will require rule changes.

Tunnels will still be safe

- Will not simpler tunnels go beyond the safety?
- No, it should be safe to drive in Norwegian tunnels. This applies to traffic safety, fire safety and hedging against stones fallout. At the same time, I have to avoid solutions that give marginal benefits, so that there is room to realize other projects faster, says Slinde.

Will reduce interest costs
The proposal to reduce the interest rate compensation contractors are allowed to win in court with a claim is the measure that is most financially most financially. The delay rate is 8 per cent plus the key policy rate for Norway's bank. Other public builders such as Bane NOR and new roads can make agreements with the contractor on lower delays.

- lower interest expenses one thing. Smaller interest rate returns may also motivate to agree before the case ends in court, says Slinde.

Important job
Director of development in the Norwegian Public Roads Administration, Kjell Inge Davik, says the expert group in the Roads Administration has done an important job of getting more tunnel for money.

-ME must build many miles of tunnel in the future to make the road network safer in Norway, and ensure better improved on the national and county roads. Then it is important that I do not build the tunnels more complicated than necessary, says Davik.

These are the tunnels the expert group in the Roads Administration has assessed:

Project
E134 Oslofjord connection, construction stage 2  9,4 km
Rv. 4 Grua - Roa                                                   1,2 km
E134 Røldal - Seljestad                                      12,7 km
E6 Megården-Mørsvikbotn                                 23,5 km
E16 Hylland - Slæn                                              6,3 km
E39 Vik - Molde                                                  24,3 km
E16 Arna - Stanghelle and Vossebanen              8,8 km - 19,0 km
E45 Kløfta                                                            4,2 km
Rv. 7 Ørgenvika - Kittilsvik                                   1,3 km
E6 Ulvsvågskaret                                                 3,7 km
E39 Ådland - Svegatjørn (Hordfast)                   19,0 km
E134 Dayslett - E18, Viker                                   4,4 km
E39 Storehaugen - Førde                                    7,5 km
E39 Bjerkeset - Astad                                          1,4 km
E39 Klakegg - Byrkjelo                                        4,0 km
E39 Ringvei Øst, Vågsbotn - Klauvaneset          5,3 km
E10 nappstraumen - to                                       1,7 km
E39 Volda - Furene                                             3,5 km
E18 Retvet - Winter Bridge                                 2,4 km
E8 Airport Tunnel Tromsø Incl. F2-Lenka           2,5 km

Photo: Use of shotcrete, Eiganes tunnel in Stavanger, Norway, by Øyvind Ellingsen/Statens vegvesen at press release: https://kommunikasjon.ntb.no/pressemelding/18044609/kan-spare-milliardar-pa-nye-tunnelar?publisherId=17847490&lang=no

Disclosure: Translation mistakes are mine.