球形颗粒流数值模拟宏细观力学强度参数相关性研究

Study on the Correlation of Meso and Macroscopic 3D Mechanical Strength Parameters of Geotechnical Granular Material Based on PFC3D

采用颗粒离散元方法研究岩土体的细观力学性质时,由于细观参数的选取具有一定的人为性和不确定性,如何确定宏、细观参数之间的关系是必须面临的难题。基于平行粘结模型,在大量数值三轴压缩试验基础上,建立了岩土颗粒材料三维细观参数(颗粒摩擦系数、颗粒接触刚度比、颗粒粘结强度、颗粒粘结强度比)与材料宏观力学强度参数(c,φ)的标定关系。结果表明:细观参数颗粒接触刚度比与颗粒摩擦系数对岩土颗粒材料的剪切强度参数(c,φ)影响较大,其他参数影响可忽略;采用多元非线性拟合方法,定量给出了相关细观参数与宏观剪切强度参数(c,φ)的计算公式;并通过一处于蠕滑状态的边坡力学状态对标定的参数准确性进行了验证。所建立的预测公式可为相关力学计算与数值模拟提供参数确定依据。

When particle discrete element method is carried out to study the mesoscopic mechanics properties of rock and soil, how to determine the relationship between the macro mesoscopic parameters must be a problems. However, the selection of mesoscopic parameters has certain artificial and uncertainty.On the basis of a large num-ber of numerical triaxial compression test, rock and soil granule material is established three-dimensional mesoscop-ic parameters （ particle contact friction coefficient stiffness than particle bonding strength of adhesive strength than the particles） and macroscopic mechanical strength parameters （ c, φ） the relationship of calibration.The results show that the mesoscopic parameters of particle contact stiffness ratio and particle friction coefficient of the shear strength parameters of rock and soil particle materials （ c,φ） , the other parameters particles ignore its influence;Using multivariate nonlinear fitting method, presented quantitative related mesoscopic parameters and macroscopic shear strength parameters （ c,φ） calculation formula and through a mechanical state of the slope in a creep state parameters corresponding relation are verified, the predicted formula can provide parameters for related mechanical calculation and simulation quickly determine the basis.