Soil–water interaction is a pivotal process in many underwater geohazards such as underwater landslides where soil sediments gradually evolve into turbidity currents after interactions with ambient water. Due to the large deformations, multiphase interactions and phase changes this involves, investigations from numerical modelling of the transition process have been limited so far. This study explores a simple numerical replication of such soil–water mixing with respect to changes in average strength using smoothed particle hydrodynamics (SPH). A uniform viscoplastic model is used for both the solid‐like and fluid‐like SPH particles. The proposed numerical solution scheme is verified by single‐phase dam break tests and multiphase simple shear tests. SPH combinations of solid‐like and fluid‐like particles can replicate the clay–water mixture as long as the liquidity index of the solid‐like particles is larger than unity. The proposed numerical scheme is shown to capture key features of an underwater landslide such as hydroplaning, water entrainment and wave generation and thus shows promise as a tool to simulate the whole process of subaquatic geohazards involving solid–fluid transition during mass transport.

中文翻译：

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土壤-水混合的平滑颗粒流体动力学模型及其平均强度的变化

在许多水下地质灾害（例如水下滑坡）中，土壤与水的相互作用是一个关键过程，在该过程中，土壤沉积物在与环境水相互作用后逐渐演变成浊流。由于涉及的大变形，多相相互作用和相变，迄今为止，对过渡过程的数值模型的研究受到了限制。这项研究使用平滑粒子流体动力学（SPH）探索了这种土壤-水混合相对于平均强度变化的简单数值复制。固体和液体SPH颗粒均使用统一的粘塑性模型。通过单相溃坝试验和多相简单剪力试验验证了所提出的数值解方案。只要固体颗粒的流动性指数大于1，固体颗粒和流体颗粒的SPH组合就可以复制粘土-水混合物。拟议的数值方案显示了水下滑坡的关键特征，例如滑水，引水和波浪产生，因此显示出有望作为模拟大规模运输过程中涉及固体-流体过渡的水下水下地质灾害全过程的工具。