Rapid consolidation characteristics of Yellow River-derived sediment: Geotechnical characterization and its implications for the deltaic geomorphic evolution

Abstract The Yellow River, which presently discharges into the western Bohai Sea, has been widely recognized as having one of the highest sediment loads on Earth. Understanding the consolidation characteristics of Yellow River-derived sediments is critical for improving our knowledge of the riverine sediment transport, depositional processes, and evolution of the Yellow River Delta morphology. In this study, we conducted in situ experiments from 2004 to 2008 at an abandoned subaqueous delta lobe (Diaokou lobe) in order to investigate the consolidation process of the sediments. Our results show that the initial consolidation of Yellow River-derived sediment is a rapid process when the excess pore-water pressure caused by sediment aggradation can completely dissipate in ~1500 min. The change in the physical and geotechnical properties during the consolidation endows the sediments with a certain shear strength. However, due to the hydrodynamic conditions, the distribution of the sediment strength is both temporally and spatially inhomogeneous scales compared to the full consolidation process. Furthermore, a hard layer can develop at the depths of 10–30 cm and the adjacent layer can become a potential sliding surface. This study offers some insight into the formation and evolution processes of the Yellow River Delta's sedimentary and geomorphic forms.