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细观参数的正确选取是离散元模拟成功的关键,然而,目前细观参数的选取具有一定的人为性和不确定性,导致分析结果的不可比性。利用颗粒材料单元体宏观力学参数和颗粒细观参数间的相关性,通过室内三轴试验的PFC3D模拟和结果的回归分析,基于线性接触模型建立了颗粒材料初始杨氏模量、初始泊松比等宏观弹性常数与颗粒法向刚度、颗粒刚度比等细观弹性常数间的经验公式。研究结果表明:对于线性接触模型,颗粒材料的初始杨氏模量和剪切模量约与围压的1/10次方成正比,并约与颗粒粒径的0.9次方成反比。初始泊松比则约与颗粒刚度比的1/14次方成正比,而与颗粒粒径几乎无关。常见砂土的颗粒刚度比为2.0～20.7。
The correct selection of mesoscopic parameters is the key to the success of discrete element simulation. However, the selection of mesoscopic parameters has certain man-made and uncertainties at present, which leads to the incomparability of analytical results. By using the correlation between the macroscopic mechanical parameters of granular materials and the micro-parameters of granular materials, the initial Young’s modulus, the initial Poisson’s ratio of granular materials were established based on the linear contact model through the PFC3D simulation and the regression analysis of the results of indoor triaxial tests. And other macro-elastic constants and particle normal stiffness, the ratio of grain stiffness and other mesoscopic elastic constants between the empirical formula. The results show that for the linear contact model, the initial Young’s modulus and shear modulus of the granular material are approximately proportional to the 1/10 th power of the confining pressure and inversely proportional to the 0.9 th power of particle size. The initial Poisson’s ratio is then approximately proportional to the 1/14 th power of the particle stiffness ratio, and has little to do with the particle size. Common sand particle stiffness ratio of 2.0 to 20.7.