Abstract：The particle breakage of granular geomaterials under loading alters the particle-size distribution and further affects their mechanical properties. In order to reveal the effects of stress level on particle breakage，a series of confined compression tests on carbonate sand and quartz sand were conducted to investigate the compressive deformation，the stress-strain relation，the variation of particle-size distribution and the behavior of particle breakage at high compressive stress. A mathematical model was established to describe the relationship between the void ratio，the volumetric strain，the relative breakage and the stress level. Once the fractal distribution of granular geomaterials was caused by the growth of particle breakage with the increases of stress level，the ratio of volumetric strain to relative breakage remained constant. The constant ratio implies that the relative breakage may be estimated from the volumetric strain，and the value of constant ratio of quartz sand is larger than that of carbonate sand. The relationship between the increment of the pore ratio，the volumetric strain，the relative breakage and the stress level can be described respectively with a mathematical model of unified functional pattern if the particle-size distribution becomes fractal. The model can be used to predict the relative particle breakage of geomaterials in the fractal distribution stage based on the model parameters obtained from experiments.
2016, Vol. 35 
