Herrenknecht’s microtunnelling systems are currently being utilised in innovative applications around the world. “For example, during the construction of the Brandenburg Gate subway station in Berlin, Germany, a frozen pipe arch was constructed using a retractable AVN machine,” says the company.
In order to support the unstable saturated sand two AVN1200TCs drilled 30 blind holes, each with a length of approximately 90m, above the future station forming a pipe arch. After the machines had been recovered, freezing equipment was installed in the steel pipes, thereby creating a stable environment for mined excavation of the station.
For a sea outfall project near the French coastal town of Les Sables d’Olonne, an AVN1500TB was chosen to drive the outfall using pipe jacking. Work started in March 2006, driving the machine 623m out to sea through hard gneiss. “The cutter discs could be adapted to the geological conditions at any time, via access through the excavation chamber. Equipped in this way, the machine reached its target on 6 August 2006 and was then recovered,” Herrenknecht says.
Herrenknecht
Tel: +49 7824 302 0
Email: utility@herrenknecht.com
Web: www.herrenknecht.com
The AVN1500TB at work on the Les Sables d’Olonne outfall Artists impression of an AVN driven outfall
