The Motion and Deformation of Viscoplastic Slide while Entering a Body of Water

Landslide-generated waves are hazards that, commonly, exist in the natural world. The motion and deformation of a submerged landslide significantly affect the efficiency of the momentum transfer, between the slide material and the water body, and, thereby, dominate the characteristics of the associated waves. Therefore, investigating how the submerged sliding mass is moved and deformed is of great importance, not only for understanding the physical mechanism behind the slide–water interaction but also for optimizing the predictive models of the wave characteristics. In this study, we assumed the landslide as a viscoplastic fluid and used an ideal viscoplastic material, called Carbopol, to mimic a natural landslide, at the laboratory scale. We, first, determined the coordinates of three control points, including the frontal point, deepest point, and center of mass, so as to quantify the time evolution of the submerged slide motion. We, then, fit the maximums of the coordinates of the control points with an integrated parameter of the incoming landslide, with the support of experimental data. Results indicated that not only the wave features but also the submerged slide motion can be quantified by the slide parameters on impact.