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粗粒料是一定级配的岩石颗粒集合体,具有独特的物理力学特性。以粗粒料室内三轴固结排水试验成果为基础,基于离散元颗粒流理论,从细观角度出发,以PFC3D为工具,通过自编程及二次开发,得到按级配生成的粗粒料三轴试验数值模型。引入clump颗粒考虑颗粒形状对粗粒料强度及变形的影响,分析剪胀、颗粒形状、颗粒重排的关系。结果表明:颗粒形状是影响粗粒料强度与变形的主要因素,在其他细观参数一定的情况下,改变颗粒形状,可以显著影响粗粒料的力学行为;BPM模型的应力-应变关系只在低围压下与试验值吻合,随着围压的增大,偏差越来越大;而引入clump颗粒的PFC3D数值模型能很好地模拟粗粒料室内三轴固结排水试验的应力-应变特性,但由于BPM及clump都是刚性颗粒,没有考虑颗粒变形及破碎,造成应变剪胀偏大。
Coarse aggregate is a graded assembly of rock particles, has a unique physical and mechanical properties. Based on the three-axis consolidation drainage test results of coarse-grained materials, based on the discrete element flow theory, from the perspective of microstructure, using PFC3D as tool, the coarse grained material Triaxial test numerical model. The introduction of clump particles considers the effect of particle shape on the strength and deformation of coarse aggregate, and analyzes the relationship between dilatancy, particle shape and particle rearrangement. The results show that the particle shape is the main factor that affects the strength and deformation of coarse aggregate. Under the condition of other mesoscopic parameters, changing the particle shape can significantly affect the mechanical behavior of coarse aggregate. The stress-strain relationship of BPM model is only in Under the low confining pressure, the experimental data are in good agreement with the experimental data. With the increase of the confining pressure, the deviations become larger and larger. The PFC3D numerical model incorporating clump particles can well simulate the stress-strain of the coarse- However, due to BPM and clump are rigid particles, did not consider the particle deformation and crushing, resulting in strain dilatation is too large.