颗粒流模型中细观参数对粗粒土宏观力学特性的影响分析

The influence of mesoscopic parameters in particle flow model on macro-reaction of coarse grained soil

为研究黏结材料中哪些细观参数是材料力学特性宏观反应的主要影响参数,基于离散元颗粒流理论,以PFC2D为工具,自编程序,以粗粒土为黏结材料作为研究对象,以室内三轴固结排水试验作为基础,通过数值试验模拟三轴室内试验结果,并分析材料中颗粒半径大小、摩擦系数、黏结剂强度对材料宏观力学特性的影响程度。结果表明:用PFC2D模拟三轴试验,模拟结果不能精确吻合试验室内的结果;颗粒半径参数与土体强度的关系为二次函数;摩擦系数直接影响土体的摩擦角的大小,且材料摩擦角在摩擦系数较小时的影响敏感性较强;黏结剂强度直接影响材料的抗剪强度,且抗剪强度与CBSR黏结剂强度化黏呈正线性相关。在黏结剂强度取值在一定范围内,试样压缩裂隙数量随着黏结剂强度的增大而增大。

The meso- mechanicalparameters of bonding materials are the main influencefactor of materialmacroscopic reaction. The coarse grain soilwas studied based on means of PFC2 D andtriaxial consolidationtest.The influence of the macroscopic reaction was analyzed about the particle size, friction coefficient, thecontact bond strength of materials.The results show that the relationship between particle radius and soilstrength is quadratic; friction coefficient directly affects the material friction angle, and the friction angle ofmaterial influence sensitivity by friction factor is stronger when the friction coefficient is small;contact bondstrength directly affects the shear strength of materials, and shear strength was positively linear correlationwith CBSR.; when the adhesive strength values within a certain range, sample compression fracture numbersincrease with the strength of the contact bond strength.