New tunnel in loose soil under cemetery

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Cautus Geo established extensive monitoring during work on a new tunnel under a cemetery on the city railway in Bergen.

Problem statement

Construction of a new tunnel under Bergen's largest cemetery with 26,000 graves and a history dating back to 1874. The area is heavily trafficked. The new Kronstadt tunnel is part of the extension of the Bybanen railway.

Solution

Cautus Geo established a system of total stations, prisms and inclinometers across the construction site and in the tunnel. Everything was networked and connected to Cautus Web. Alarm levels were established with fixed tolerance limits. The instruments were moved forward along with the progress of the tunnel project.

The design ensured continuous monitoring with real-time data flow to the Cautus Web visualisation solution. In addition, an alarm was set up to alert plant management if tolerance limits were exceeded.

Comprehensive monitoring on the city railway

The Bergen Light Rail has been under construction for almost 15 years. Since the first section was opened in the summer of 2010, a further three construction stages have been opened. Most recently the extension to Flesland in 2016. The fourth is now underway. The railway will be extended to Fyllingsdalen via Haukeland. This will extend the line by nine kilometres. At the same time, two tunnels have been built for pedestrians and cyclists.

Cautus Geo has had several assignments during the expansion. This includes instrumentation and monitoring of the ground during work on the shaft for the underground station at Haukeland Hospital.

Track in loose masses

The 470-metre Kronstad tunnel provides cyclists with a fast and safe route between Bergen city centre and Kronstad. It is partly the result of extensions and improvements to the old railway tunnel and partly a new tunnel, established in loose masses in a busy urban environment.