The paper deals with the interaction mechanisms that develop when a flow-like mass movement hits a protection barrier. Propagation-impact experiments were conducted in the Geo-Centrifuge of Deltares (Delft, Netherlands) at 40 g-level and they consisted of releasing a saturated soil mass that propagated along an instrumented slope and finally impacted against a barrier. Different protection structures, rigid and fixed to the ground as a reinforced concrete wall or deformable and free sliding as a geosynthetics-reinforced barrier were tested. The structure's height relative to flow depth also varied. A natural Vesuvian volcanic soil, prone to static liquefaction upon shearing, was used for the first time. This is a major novelty compared to uniform particle-size material previously used in the literature. As benchmark cases, solely water and a well-documented Baskarp sand from Sweden were also used. The impact pressure, total stresses and pore water pressure during the flow and the impact were measured. Insights on the role of fine content were obtained to update the design criteria for the protection barriers. The first analysis of the tests showed that the magnitude of the peak impact pressure and its time dissipation is apparently influenced by granulometry of flow and type of barrier. The particle size regulates the flow dynamics and landslide-structure interaction, and finally results in different impact mechanisms, and type of landslide-structure interaction such as dead zone formation, run-up and/or overtopping.
5th European Conference on Physical Modelling in Geotechnics (ECPMG2024)
Geotechnical infrastructure