韩振华, 张路青, 周剑. 2019: 基于PFC2D模拟的矿物粒径非均质效应研究. 工程地质学报, 27(4): 706-716. DOI: 10.13544/j.cnki.jeg.2017-148
    引用本文: 韩振华, 张路青, 周剑. 2019: 基于PFC2D模拟的矿物粒径非均质效应研究. 工程地质学报, 27(4): 706-716. DOI: 10.13544/j.cnki.jeg.2017-148
    HAN Zhenhua, ZHANG Luqing, ZHOU Jian. 2019: EFFECT OF MINERAL PARTICLE SIZE HETEROGENEITY ON MECHANICAL PROPERTIES IN PFC2D SIMULATION. JOURNAL OF ENGINEERING GEOLOGY, 27(4): 706-716. DOI: 10.13544/j.cnki.jeg.2017-148
    Citation: HAN Zhenhua, ZHANG Luqing, ZHOU Jian. 2019: EFFECT OF MINERAL PARTICLE SIZE HETEROGENEITY ON MECHANICAL PROPERTIES IN PFC2D SIMULATION. JOURNAL OF ENGINEERING GEOLOGY, 27(4): 706-716. DOI: 10.13544/j.cnki.jeg.2017-148

    基于PFC2D模拟的矿物粒径非均质效应研究

    EFFECT OF MINERAL PARTICLE SIZE HETEROGENEITY ON MECHANICAL PROPERTIES IN PFC2D SIMULATION

    • 摘要: 岩石作为矿物颗粒的集合体,矿物粒径非均质性对其宏观力学特性影响比较明显。基于颗粒流程序PFC2D,通过设置不同种类粒径组合及粒径比来体现粒径非均质性,研究了粒径非均质性对岩石材料宏观力学特性(弹性模量、峰值强度、泊松比)的影响。研究中设计了6种粒径组合方案,粒径种类数分别为:连续粒径、10种、8种、5种、3种、2种,每种方案下设置5种平均粒径及4种粒径比,进行单轴压缩试验。结果表明,岩石内部存在颗粒尺寸效应和粒径非均质效应,岩石弹性模量和峰值强度随粒径增大均呈减小的趋势,随粒径非均质性的提高整体上也呈减小的趋势,但局部变化阶段受模型中细颗粒含量及数量的影响会呈增大的趋势。粒径对弹性模量的作用机制主要是通过影响模型孔隙率实现的。研究结果揭示了岩石宏观特性的变化是模型内颗粒尺寸效应和粒径非均质性效应共同作用的结果,为掌握矿物粒径对岩石强度及变形特性的影响提供了一定依据。

       

      Abstract: As aggregates of mineral particles, the macroscopic mechanical behaviors of rock are obviously affected by mineral particle size and size heterogeneity. The effect of size heterogeneity on rock macroscopic mechanical behaviors(elasticity modulus, peak strength and poisson's ratio) is studied using the software of particle flow code PFC2D. Different kinds of particle sizes are included in a model and size ratio are used to reflect particle size heterogeneity. Six size heterogeneous scenarios are designed and conducted in the numerical uniaxial compression tests. The type numbers of particle sizes included in a model are respectively continuous distribution, ten kinds, eight kinds, five kinds, three kinds and two kinds. Each scenario includes five mean grain sizes and four size ratios. The results show that particle size and size heterogeneity play an important role in the macro-mechanical properties of these numerical tests. Elasticity modulus and peak strength of samples decrease with the increase of average particle size. With the increase of the size heterogeneity, elasticity modulus and peak strength also show a decreasing trend overall, but during some local change stages show an increasing trend affected by the number and content of fine particles. The effect of particle size and size heterogeneity on Poisson's ratio is smaller. The effect mechanism of particle size on elastic modulus is mainly achieved by influencing the porosity of the model. The achieved results disclose that the change of rock macroscopic properties is the combined action of particle size effect and size heterogeneity effect, and supply references for studying the influence of particle size parameters on strength and deformation feature of rock materials.

       

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