Laws of underwater accumulation of nonuniform triple particles

Abstract

Artificial coastal accumulation is a key link in the reclamation and island-building project. Due to the different particle sizes and contact slope angle of the accumulation, the accumulation body presents complex particle distribution, accumulation form, and internal structure, which affects the overall safety and stability of coastal accumulation. In this paper, the combination of physical model test and numerical simulation analysis is used to study the accumulation process and mechanism of particles as well as the distribution law of particles in the accumulation body. The results showed that the formation of the accumulation is a dynamic process of the combined action of multiple forces. The distribution of the accumulation particles is as follows: fine particles (size) are mainly distributed near the surface and bottom of the slope. Medium particles (size) are uniformly distributed throughout the accumulation, while the coarse particles (size) are mainly distributed in the upper part of the accumulation. Moreover, this distribution pattern became increasingly evident with an increase in slope angle. In particle accumulation, the leading edge particles are propelled by both following particles and finer particles in infiltration gaps, and the particle movement path fluctuates. The average coordination number of particles in each direction and layer of accumulation bodies is positively correlated with the total mass percentage of particles. The maximum coordination number that occurred in the second layer of the X-direction (plane vertical) was 5.45, the first layer of the Z-direction (vertical) was 5.46, and each layer of the Y-direction (horizontal) with symmetric distribution ranged from 5 to 6. The 45° slope had the largest average coordination number in each layer among slopes with different angles.