Undrained true triaxial response of initially anisotropic particulate assemblies using CFM-DEM

Abstract

Abstract While simulation of the drained true triaxial response of particulate assemblies using discrete element method (DEM) has caught the attention of researchers in the recent years, simulation of the undrained condition under generalized stress condition has not yet been well addressed in the literature. This treatment suggests an applicable coupled fluid-discrete element scheme to simulate the undrained response of initially anisotropic particulate assemblies under true triaxial condition. Coupled fluid-discrete element simulations highlight the combined impact of Lode angle and anisotropic microstructure of the assemblies on the effective stress paths, mobilization of shear strength, and accumulation of pore-water pressure under undrained condition. For loose assemblies suffering from flow instability, it is shown that stress ratio, mobilized friction angle, and pore-water pressure at the onset of instability depend on Lode angle.