Influence of Topographical Slope Variations on Movement Behavior of Viscous Submarine Landslides Based on Incompressible Smoothed Particle Hydrodynamics

Abstract:

To address the challenges posed by intense hydrodynamic interaction between sliding masses and ambient water in submarine landslide dynamics， this paper developed a coupled two-phase flow （incompressible smoothed particle hydrodynamics）ISPH model incorporating particle shifting and gradient correction techniques to enhance numerical stability. The model was validated against underwater landslide experiments and then applied to analyze the impact of terrain variations on landslide evolution. The results indicate that the landslide exhibit the strongest dynamic performance at the characteristic corner， with the sliding distance increasing by approximately 14% compared to other conditions. Steeper slope changes tend to trigger fluid uplift， promoting particle dispersion and turbidity current formation， thereby increasing the risk of damage to underwater infrastructure. Unlike dry conditions， submarine landslides display a two-stage dynamic behavior， where momentum exchange between particles and fluid sustains continued motion over flat regions， partially explaining long-runout phenomena.