Abstract To provide data for the numerical modelling effort on the impact of seabed nodule harvesting on the marine environment and infrastructure, an experimental study of the interaction between a simple lab-scale nodule harvester and sediment/sand is carried out. The lab-scale harvester is simplified by a moving inclined plate and the seabed sediment is modelled by a tank containing water and bentonite suspension, or sand, as sediment substitute. The forces acting on the plate by the sediment are measured and the dispersion of sediment particles in the water tank is visualized. Experiment results show that, for a high enough mass fraction, the bentonite suspension displays a yield-stress behavior; and indeed, a gel-like structure suspension may result. Sand, being non-cohesive in nature, gives a much greater acting force on the plate than bentonite sediment. Gel-like structure clay suspension gives a much greater force than fluidified suspension. Once dispersed into water, sand particles quickly settle while clay particles take a longer time to settle and form an emulsion layer on top of the sediment. The experiment results serve both as a means to calibrate and validate the numerical modelling, as well as to gain physical insights into the seabed/structure interaction.

中文翻译：

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倾斜板移动沉积物/沙床的力测量

摘要 为了为海底结核采集对海洋环境和基础设施影响的数值建模工作提供数据，对简单实验室规模的结核采集器与沉积物/沙子之间的相互作用进行了实验研究。实验室规模的收割机通过一个移动的倾斜板进行简化，海底沉积物由一个装有水和膨润土悬浮液或沙子的水箱模拟，作为沉积物的替代品。测量沉积物作用在板上的力，并可视化水箱中沉积物颗粒的分散情况。实验结果表明，对于足够高的质量分数，膨润土悬浮液表现出屈服应力行为；事实上，可能会产生凝胶状结构的悬浮液。沙子，在本质上是非粘性的，对板上的作用力比膨润土沉积物大得多。凝胶状结构粘土悬浮液比流化悬浮液提供更大的力。一旦分散到水中，沙粒会迅速沉降，而粘土颗粒则需要更长的时间才能沉降并在沉积物的顶部形成乳状液层。实验结果既可作为校准和验证数值建模的手段，也可作为对海床/结构相互作用的物理洞察力。