Rheological properties of deep-sea sediment flows with different sediment grain sizes and concentrations

Submarine sediment flows, as the primary transport mechanism for deep-sea sediments, are a crucial component of the marine sediment “source-sink” system. The type and movement velocity of sediment flows are governed by their rheological properties, which fundamentally depend on the variations in sediment grain size composition and concentration. To accurately describe the processes and velocities of sediment flows, as well as to predict its potential disaster effects and impacts, it is essential to obtain precise rheological characteristics of sediment flows with differing sediment grain sizes and concentrations. This study employs a rheometer to measure the rheological properties of sediment flows with varying sediment grain sizes and concentrations. It presents the threshold values of sediment content at which the fluid properties of sediment flows change for different grain sizes. The results indicate that the rheological behavior of sediment flows transitions from Newtonian to Bingham fluid and ultimately to pseudoplastic fluid types with increasing concentration. Additionally, variations in grain size govern the critical concentrations at which these fluid-type transitions occur. The foundational data on the rheological property transitions of sediment flows, as revealed by the research findings, exhibit broad applicability. These data can support the simulation of sediment flow movement and evolution processes and contribute to the prediction of sediment flow velocity.