Based on the stochastic granular discontinuous deformation(SGDD) method, a cohesive zone model is employed to simulate the breakage of coarse aggregates. In this model the cohesive interface elements are inserted into the region of coarse aggregates; and the constitutive response of cohesive element is governed by an energy-based damage evolution law. If the interface between these sub-particles breaks, the breakage will happen. By using this model, it is possible to study the influence of particle breakage on the macroscopic properties of the rockfill, such as volumetric strain, shear strength and dilatancy angle. The numerical simulation results reveal that the strength of the coarse-grained material can significantly decrease due to particle breakage. The mechanism of this phenomenon lies in the weakening effect of dilatation due to particle breakage. Along with particle breakage, the acoustic emission(AE) occurs; and the AE count under higher confining pressure is greater than that under lower confining pressure. In the shear process, the contact normal orientation between particles is inclining gradually from horizontal direction to vertical direction. Furthermore, the main direction of normal contact force is the same as the loading direction; and the average normal contact force between particles increases gradually.%基于随机颗粒不连续变形模型,在颗粒的细观单元之间插入界面单元,采用黏聚力裂缝模型模拟界面单元的起裂、扩展和失效,研究颗粒破碎对堆石体强度和变形的影响.从宏观、细观2个层面分析细观数值模拟结果,结果表明:本文提出的方法能直接模拟三维颗粒破碎现象,颗粒破碎降低堆石体的强度,其机制在于颗粒破碎弱化堆石体的剪胀性能,使得由于剪胀引起的内摩擦角显著降低,颗粒破碎的影响随围压的增加而增大；颗粒破碎时伴随着声发射,高围压下声发射数多于低围压下,表明高围压下颗粒破碎更明显,与试验结果一致;在剪切过程中,颗粒间接触法向逐渐由水平方向向竖直方向倾斜,法向接触力的主方向与加载方向相同,颗粒间平均法向接触力逐渐增大.
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