Abstract:

The erodibility change of estuarine sediment in the process of consolidation directly determines the resuspension and secondary migration of sediment, which plays an important decisive role in estuarine and coastal stability. The rapid deposition of Yellow River sediment into the sea was simulated on the tidal flat of the modern Yellow River delta, and the erodibility and physico-mechanical properties of the sediment at different consolidation times were measured in situ. The results show that the anti-erodibility of the Yellow River sediment into the sea rapidly increases with consolidation time; and the critical erosion shear stress has already exceeded the value of the undisturbed tidal flat surficial sediment when the consolidation time extends as long as 8 hours. The critical erosion shear stress of the newly deposited sediment has a good positive correlation with bulk density, penetration resistance and shear strength, a good negative correlation with water content. The rise rate of measured critical erosion velocity of the Yellow River sediment into the sea with consolidation time is higher than the rise rate of calculated value using different formulas; and the former is 1.5-4.1 times as high as the latter.

Key words: Yellow River estuary, sediment into the sea, consolidation process, critical erosion shear stress, field experiments