Large scale triaxial test and discrete element-finite element coupling simulation of mechanical properties of coarse-grained soil
This article investigated the mechanical properties of coarse-grained soil to identify the internal relationship between its micromechanical fabric and the characteristics of its macroscopic deformation.By integrating laboratory-scale triaxial tests and discrete element-finite element coupling-based simulations,we established a three-dimensional numerical model of coarse-grained soil to replicate the content and shapes of large stone blocks.We used flexible confining pressure-induced loading and rigid block technology to optimize the microscopic models of the stone blocks,and conducted comprehensive numerical simulations of coarse-grained soil specimens by using the PFC(Partical Flow Code)program.The findings showed that the specimens exhibited a strain-hardening effect.Under a flexible confining pressure-induced loading,the specimens exhibited lateral bulging-induced deformation and developed"X"-shaped shear bands in the central region.The chains of the vertical contact force gradually intensified,and exhibited a trend of interconnection.Our comprehensive analysis of the macroscopic deformation and micromechanical fabric of the soil showed that the degree of deformation caused by its compression along the vertical direction was more significant than that caused by its shear failure along the radial direction,and the degree of change in its vertical anisotropy was greater than that in its horizontal anisotropy.This indicates that the trend of changes in its micromechanical fabric and the characteristics of its macroscopic deformation were clearly consistent.
triaxial testingcoarse-grained soildiscrete element-finite element couplingmicrostructure
万方数据
维普
