Micro-mechanical analysis of particle shape effect on suffusion of gap-graded soils

Suffusion refers to the process of fine particles carried away from a coarser soil matrix by seepage flow. Numerical simulations of coupled fluid–solid methods are wildly used in analyzing micro and macro behaviors of gap-graded soils during suffusion. However, the solid particles are usually simplified to spheres, resulting in inaccurate detachment, transmission and clogging mechanisms. In this study, the complex particle shape factor is taken into account in CFD–DEM. A series of numerical tests were conducted to explore the effects of aspect ratio both for fine and coarse particles. Macroscopic and microscopic information of suffusion process is obtained. Numerical results indicate that particle shape plays a significant role in suffusion.