Particle erosion in suffusion under isotropic and anisotropic stress states

Abstract

In this study, a set of laboratory experiments is conducted to investigate the erosion behaviors of soils subjected to suffusion under isotropic and anisotropic stress states. The results show that the amount of eroded particles gradually increases with the erosion time under isotropic stress states. The final accumulative particle loss approaches a constant if the erosion time is sufficiently long under a given erosion gradient. The erosion behaviors under anisotropic stress states are similar to those under isotropic stress states, as long as the amount of particle loss is small. However, if the erosion amount is high enough to reach a critical value, the specimen collapses and undergoes significant volumetric deformation. Based on these erosion behaviors, an analytical expression for the erosion rate is developed to quantify the erodibility of cohesionless soils. Moreover, an energy-based model is used to interpret the erodibility of soils. The mechanism of the effects of the stress state on the erosion behaviors, especially the collapse of specimens, is explained. It is concluded that the evolution of the strain-stress behaviors and the rearrangement of the microstructure are the main reasons for the differences between the erosion behaviors under isotropic and anisotropic stress conditions.