Flexible debris flow nets were developed within a three-year Ph.D. thesis by Wendeler in 2008. Since then, they have been used all over the world for debris flow protection or slope/riverbed stabilization.
Some of these installed flexible debris flow nets have already been filled a couple of times, and the developed load model has been proved. Nevertheless, depending on soil properties, most problems appear to be of constructive nature such as channel bank erosion which exposes anchors or undermining supporting foundations if water constructive methods are not solved correctly. Both cases lead to instability of the entire system and increased maintenance costs and should, therefore, be avoided.
Today, we present the first research on a serviceability method for scour and erosion issues on flexible debris flow nets. The results are based on an analysis of already existing barriers to determine occurring scour and erosion problems. Planning engineers will be able to design and calculate their debris flow protection system more economically and safely. Further, maintenance costs will be minimized and a longer lifetime of the entire barrier system, including the anchors as the most cost-intensive parts, can be provided.
Find some impressions of the small field tests.
Nadine Feiger, who did her master's thesis (ETH Zurich) on "Flexible debris flow barriers and their service ability proof" will be presenting at the 7th International Conference on Debris-Flow Hazards Mitigation, in Golden, Colorado.