中文摘要：

荷载作用下粒状岩土材料的颗粒破碎改变了粒径分布,从而影响其力学特性。为了揭示应力水平对颗粒破碎的影响规律,利用一系列高压应力下的侧限压缩试验研究钙质砂和石英砂的压缩变形、应力–应变关系、粒径分布的演化和颗粒破碎特性。在此基础上,建立描述粒状岩土材料的应力水平与孔隙比、体应变、相对破碎率等相关关系的数学模型。研究结果显示：无论是钙质砂还是石英砂,随着应力水平的增加,一旦颗粒破碎增长致使砂粒趋向分形分布,体应变与相对破碎率的比值将保持恒定。恒定比值意味着基于体应变就可估算相对破碎率,其数值为石英砂大于钙质砂。如果颗粒分布发展至分形分布,其孔隙比、体应变、相对破碎率的增量随应力水平的变化规律,可以用形式统一的数学模型表达。基于试验获得的模型参数,该模型可用于预测颗粒在分形分布阶段的相对破碎率。

英文摘要：

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.