This study presents a numerical model that couples the Discrete Element Method (DEM) with the Lattice Boltzmann Method (LBM) to investigate the influence of pore pressure on submarine landslides impinging against cables. DEM is employed to simulate the mechanical behaviour of granular materials, while LBM models the fluid dynamics of pore water. This coupled approach enables a detailed analysis of the interactions between submarine landslides and submarine cables, capturing the dynamics of pore pressure and its effect on the velocity field of both grains and fluid. The model has been benchmarked against values from the literature, demonstrating its reliability and accuracy in reproducing observed phenomena. Results highlight the critical role of pore pressure on the velocity field and forces acting on intruders.

Abstract: Granular flows are typically studied in laboratory flumes based on common similarity scaling, which create stress fields that only roughly approximate field conditions. The geotechnical centrifuge produces stress conditions that are closer to those observed in the field, but steady conditions can be hardly achieved. Moreover, secondary effects induced by the apparent Coriolis acceleration, which can either dilate or compress the flow, often obscure scaling. This work aims at studying a set of numerical experiments where the effects of the Coriolis acceleration are measured and analyzed. Three flow states are observed: dense, dilute, and unstable. It is found that flows generated under the influence of dilative Coriolis accelerations are likely to become unstable. Nevertheless, a steady dense flow can still be obtained if a large centrifuge is used. A parametric group is proposed to predict the insurgence of instabilities; this parameter can guide experimental designs and could help to avoid damage to the experimental apparatus and model instrumentation.