Control of the Opera Tunnel and salmon in the Akerselva river

The 1,000 square metre museum pillar will be established in the middle of the nine-kilometre-long harbour promenade in Oslo, in front of the Munch Museum, which marks the entrance to the Akerselva river.

The exit will be on the outside of the Opera Tunnel. It will be accessible to everyone with a 30 metre long bridge. The development is taking place in a sensitive area. The Opera Tunnel is heavily trafficked, and the Akerselva river is important for salmon and sea trout.

Pore pressure gauges have been installed on both sides of the Opera Tunnel. They are located at different heights, from 25 to 40 metres below the seabed.

- The meters continuously check the pressure and send data in real time to Cautus Web. An alarm has been set up with SMS and e-mail notification if the pressure outside the heavily trafficked Opera Tunnel should fall or rise," says project manager Sigmund Brekke Langelid of Cautus Geo.

Cautus Geo will also monitor water quality. Water quality meters have been established in floating buoy stations. These stations also send data in real time to Cautus Web.

This summer there will be digging and dredging in the area. And 60 piles will be installed during the construction period. It is therefore important to monitor the water quality.

- We are concerned about safety and biodiversity. The museum extension will be established at the mouth of the Akerselva river. We need to have data to show that the establishment will not jeopardise the water quality or salmon runs in the river," says Kristine Langfjord, Head of Communications for the cultural buildings in Bjørvika at Kultur og idrettsbygg.

NRC Anlegg is the contractor. About the choice of Cautus Geo, the company says:

- The Museum Explorer is a complex project. Anything that can simplify and streamline is important. Cautus Geo gives us a clear and reliable solution that is easy to use," says project manager Martine Stang Johnsson at NRC Group Norway.

Facts about Museumsutstikkeren

• The client is the City of Oslo by Kultur og Idrettsbygg Oslo KF
• NRC Anlegg AS has been commissioned to establish the protrusion
• Work started in June and will be completed in spring 2020
• The site is 1,000 square metres with a square, pier and quay
• A 30 metre long bridge is being built out to the extension itself

Cautus Geos mission

• Seven pore pressure gauges at depths from 25 to 40 metres below the seabed on both sides of the Opera Tunnel
• Two floating buoy stations measure water quality, turbidity or suspended solids in the water, during the construction period
• Since May, the meters have been sending real-time data to the Cautus Web portal with automatic SMS and email alerts based on pressure and water quality thresholds.

Cautus Geo AS is an independent company specialising in the development, establishment and operation of various measurement systems. Our goal is to be a leading and developing player in efficient and secure solutions for monitoring structures, land, water, climate and the environment.