Interaction of flowslides with fixed and movable barriers: centrifuge tests on Baskarp and Vesuvian soils

The paper investigates the interaction of saturated flows propagating along a slope and finally impacting a barrier (a) fixed to the base ground or (b) movable, i.e., free to slide along the base ground. Two volumes are considered, two positions of the barrier (near or far), and two soils (a monogranular medium sand and a volcanic silty sand). The tests are conducted at 40 g in a small-scale centrifuge model using the GeoCentrifuge, which is available at Deltares in Delft. Measurements are achieved through high-speed cameras and high-frequency load cells. Some major insights are that: (a) the presence of fine promotes long-lasting flow-barrier interaction, (b) the load transferred to the movable barrier is lower than the fixed barrier, (c) the ratio of lateral and vertical pressure inside the flow front drastically changes over time, (d) a statistic is achieved for both such ratio and the lateral soil pressure. Despite the substantial number of tests considered, the main limitations relate to: the specific geometric configuration of the slope considered; the limited number of load cells and cameras installed. Coupling the experimental results with numerical modeling represents a promising direction for future research.