Study of variation of pore properties in gravel soil under triaxial loading based on discrete element method

Gravel soil is a complex porous medium, whose mecha­nical behaviour under triaxial loading can be well simu­lated using the discrete element method. However, numerical simulation of porous medium under compression requires not only the stress–strain behaviour, but also the variation of pore properties. In this study, models of gravel soil with different gravel contents (weight percentage of gravel in gravel soil) are generated by the single particle delivery method, and numerical triaxial tests are performed on these gravel soil samples. The equivalent porosity and equivalent pore size are introduced as evaluation indexes of pores to study the variation of pore properties in the numerical tests. The numerical results indicate that the porosity of gravel soil shows a V-shaped trend with the gravel content, and the gravel soil samples have minimum porosity in the yield stage.