Snowcatcher – full-scale test site in the Stubai Valley

Siglufjörður

2019

6 S.

Sonderdruck

205089

International Symposium on Mitigative Measures against Snow Avalanches and Other Rapid Gravity Mass Flows: Siglufjörður, Iceland, April 3–5, 2019 (2019) , 6 S.

Avalanche protection structures such as snow bridges, rakes and nets in release zones, as well as dams for catchment or deflecting structures in run-out and deposition zones, have been suc-cessfully employed for many years. More recently, the idea of using flexible-net catchment fences as lightweight, space saving and economic alternatives, aimed at shortening the run-out distance of avalanches, has been proposed. A full-scale structure, the so-called Snowcatcher, was installed and instrumented with several load measuring pins, which record the dynamic forces caused by an avalanche. Two avalanche events were recorded and allow to investigate the temporal force evolution and observed peak values. The results indicate significant differ-ences in the measurement results. It appears that the difference in size and structure-avalanche interaction, as well as the existence of debris material in the avalanche flow is of major im-portance for the observed forces. This additional debris material blocks the net surface, making it impermeable and prevent snow particles from passing the net surface. Further the debris – structure impact leads to peak forces that may damage parts of the structure.