Abstract: The process of sedimentation and consolidation of soil particles in dredged slurry is very complex, and it is not clear about the sedimentation and consolidation of soil particles. A modified experiment method which is called multilayer extraction sampling is adopted in laboratory test. The volume distribution regularity of soil particle is firstly obtained, and then the average settlement velocities of soil particles in different soil fractions by using volume flux function method are calculated. The result reveals that: there are three different zones existing during the sedimentation and consolidation of soil particles in dredged slurry. They are hindered settlement zone, floc compression settlement zone and self-consolidation zone separately. During the first hour and the next 6 hours, the velocity of soil particles is much smaller than the velocity calculated by using Stokes equation in hindered settlement zone, and it is related to the particles diameter of 0.488 1 and 0.111 7 th power. There is no separation of soil particles in floc compression settlement zone and self-consolidation zone. All soil particles in these two zones are belong to the sediments. The density of floc compression settlement zone is about 1.04 g/cm3.

Key words: dredged slurry, volume flux function, sedimentation-consolidation, Stokes, floc compression settlement