Static and dynamic FE analysis of an RC protective structure dedicated to snow avalanche mitigation

Snow avalanches threaten more and more people and different types of structures in mountainous areas. This study focuses on a protective RC (reinforced concrete) structure consisting of an L-shaped wall. The objective of this paper is to calibrate and validate a 2D FE (Finite Element) model in order to explore the behavior of such RC structures loaded by pressure time signals caused by snow avalanche flows and to assess their vulnerability. Four concrete constitutive laws were tested to accurately describe the total collapse of the structure obtained from a pushover test carried out on a physical 1/6-scale model. Only two of four allowed converging up to the collapse of the wall. Then, the FE model was used to investigate the mechanical response of the wall under dynamic avalanche loading. The result shows that three types of structural responses can occur depending on the impulse of the loading signal: quasi-static, dynamic or impulsive. In the case of dense-snow avalanche loadings, the response of the wall can be described as quasi-static. Nevertheless, this conclusion should be interpreted cautiously. Indeed, avalanche impulses depend on many factors (type of avalanche, density, temperature, etc.) underlining that different structural responses might be expected.