National Road 354 Høgenhei tunnel is in Bamble municipality between Brevik bridge and
Grenland bridge. The tunnel shall be renvoated, as well as upgraded in accordance with the Tunnel Safety Regulations.
The work in the tunnel consists of laying completely new surface water installations with manholes. Construction of a new road construction in the tunnel, completely new systematic rock protection in the form of bolts and shotcrete. Assembly of VG protection for knol in parts of the tunnel. Demolition of and casting of a new concrete guiding edge on 1 side.
There will also be comprehensive electro work with new conduits, cabling, earthing
cable manholes, cable risers, lighting, cameras, emergency cupboards, signage etc.
A break-down lay-by shall be constructed outside the tunnels on each side with a new technical building. These are planned as an element building. In addition sedimentation tanks shall be constructed on the west side on the opposite side of the road to the technical building. The existing technical building shall also be renovated.
The electro outside the tunnel consists of conduits, cabling, as well as the delivery and assembly in the
technical buildings. In addition lighting shall be assembled on the existing barriers as well as new signage with flashing red lights by the eastern barrier.
The tunnel is planned to be completely closed for approx. 2 months. The remaining work after 2 months shall be carried out in the evenings and at night.