Abstract Many hazardous natural phenomena like debris flows, avalanches and submerged landslides are governed by the interactions between solid grains and interstitial fluid. They display a complex interplay of physical mechanisms, which are still very challenging to simulate with numerical methods. Different methods have been proposed in the literature to achieve this goal. This paper compares the results of two different numerical approaches: (i) a macromechanical continuum approach with the two-phase double-point Material Point Method (MPM) and (ii) a micromechanical approach with Discrete Element Method coupled with the Lattice Boltzmann Method (DEM-LBM). With the objective of highlighting potentialities and critical points of the two approaches, we conduct saturated granular column collapses in a small-scale laboratory experiment, subsequently reproduced by the numerical codes. Unlike previous experiments of collapse under gravity in dry or completely submerged conditions, in this paper the saturated material is released in air. These conditions better reproduce real natural onshore landslides and allows a discussion on the solid–fluid interaction.

中文翻译：

---

空气中饱和颗粒柱坍塌的数值与实验研究

摘要 许多危险的自然现象，如泥石流、雪崩和水下滑坡，都是由固体颗粒和间隙流体之间的相互作用控制的。它们显示了物理机制的复杂相互作用，使用数值方法进行模拟仍然非常具有挑战性。文献中提出了不同的方法来实现这一目标。本文比较了两种不同数值方法的结果：(i) 使用两相双点材料点法 (MPM) 的宏观力学连续介质方法和 (ii) 使用离散元方法与格子玻尔兹曼方法相结合的微观力学方法（ DEM-LBM）。为了突出两种方法的潜力和临界点，我们在一个小规模的实验室实验中进行了饱和颗粒柱坍塌，随后由数字代码再现。与之前在干燥或完全淹没条件下重力作用下坍塌的实验不同，在本文中，饱和材料被释放到空气中。这些条件更好地再现了真实的自然陆上滑坡，并允许讨论固液相互作用。