考虑堆石料颗粒形状的大三轴数值模型构造

Numerical Model Based on the Shape of Rockfill Material

离散元数值试验是研究堆石料力学特性的重要手段之一。堆石料颗粒形状不规则且粒径跨度大,很难形成既考虑颗粒形状,又满足实验室级配和孔隙率要求的离散元数值试样。在研究傅里叶描述符对颗粒延伸率、纵横比、扁平度等形状描述指标影响的基础上,构造了一系列不规则形状的细观堆石颗粒。结合离散元方法,采用Clump-ball混合的落雨式分层过压建模法构造了大三轴数值模型。结果表明,构造方法更接近实验室制样过程,数值模型满足室内试验级配和孔隙率要求,为研究颗粒形状对堆石料力学特性影响作铺垫。

Discrete element numerical test is one of the important means to analyze the mechanical properties of rockfill.The shape of rockfill particles is irregular and particle size span is large,therefore it is difficult to form discrete element numerical samples,which not only consider the particle shape but also meet the requirements of grading and porosity.A series of rockfill particles with irregular shapes were simulated based on the study of the influence of Fourier descriptors on shape description indicators including shape elongation,aspect ratio and flatness.Combined with the discrete element method,a large triaxial numerical model was constructed by using the Clump-ball mixed rain-drop layered overpressure modeling method.The results show that the construction method is closer to the laboratory sample preparation process,the numerical model can meet the requirements of laboratory test gradation and porosity,and can be used as a foundation to further analyze the influence of particle shape on the mechanical properties of rockfill.