Evolution Process and Hardening Mechanism of Consolidated Silt in Silty Seabed Subject to Waves

In this study, the entire evolution process of consolidated silt in a silty seabed under the action of waves is reproduced via a flume experiment. The response of pore water pressure in the seabed, variation of soil strength, and change in characteristic parameters of the soil particles are studied. From the experiment, the silty seabed is inferred to undergo two stages, i.e., failure and reconsolidation, finally forming a high-strength consolidated silt layer. The rapid accumulation of pore water pressure in the seabed under the action of waves provides the initial conditions for the formation of consolidated silt. The shear of the wave and seepage of pore water pressure provide power for the reconsolidation of the seabed. Macroscopically, reconsolidation of an unstable seabed results in consolidated silt. Microscopically, consolidated silt is the product of coarsening, homogenization, and embedment of particles. The hardening mechanism of consolidated silt is driven by increases in the internal friction angles of the particles and existence of hardening forces between the particles. The empirical formula for the internal hardening force of consolidated silt is obtained experimentally.