Investigation on the effectiveness of the catch-fence "Snowcatcher" as avalanche protection system

To date, the only available structures for mitigating avalanches in motion in the track or run-out zones of avalanches have been rigid structures such as dams or walls. Described herein, a more flexible, cost-efficient and space-saving solution has now been developed that is deemed a "Snowcatcher". The Snowcatcher consists of the highly flexible Omega-Net, bearing ropes, steel beam posts and energy dissipating devices. These primary components are all known from their use in dynamic rockfall protection barriers. The foundation of the system is realized using mono bar anchors. To investigate the effectiveness of these systems, a research project was initiated in 2008 for which a test site was built in an avalanche track in the ski area of Lech, Austria. A Snowcatcher system was installed with various force sensors throughout the structure to monitor forces during an event. Prior to the release of an avalanche through explosives, the slope is scanned using a laser and again after the event. In addition, a radar system is used to record the velocities during the avalanche. In this paper, the test site, the Snowcatcher system and the results from the first winter of tests (8 avalanches in total) is discussed.