李进昭, 徐金明, 黄大勇. 2015: 考虑细观组分实际分布的花岗岩变形破坏过程颗粒流模拟. 工程地质学报, 23(s1): 84-89. DOI: 10.13544/j.cnki.jeg.2015.s1.013
    引用本文: 李进昭, 徐金明, 黄大勇. 2015: 考虑细观组分实际分布的花岗岩变形破坏过程颗粒流模拟. 工程地质学报, 23(s1): 84-89. DOI: 10.13544/j.cnki.jeg.2015.s1.013
    LI Jingzhao, XU Jinming, HUANG Dayong. 2015: PARTICLE FLOW SIMULATION OF DEFORMATION AND FAILURE MECHANISM OF GRANITE BASED ON ACTUAL DISTRIBUTIONS OF MESO-COMPOSITIONS. JOURNAL OF ENGINEERING GEOLOGY, 23(s1): 84-89. DOI: 10.13544/j.cnki.jeg.2015.s1.013
    Citation: LI Jingzhao, XU Jinming, HUANG Dayong. 2015: PARTICLE FLOW SIMULATION OF DEFORMATION AND FAILURE MECHANISM OF GRANITE BASED ON ACTUAL DISTRIBUTIONS OF MESO-COMPOSITIONS. JOURNAL OF ENGINEERING GEOLOGY, 23(s1): 84-89. DOI: 10.13544/j.cnki.jeg.2015.s1.013

    考虑细观组分实际分布的花岗岩变形破坏过程颗粒流模拟

    PARTICLE FLOW SIMULATION OF DEFORMATION AND FAILURE MECHANISM OF GRANITE BASED ON ACTUAL DISTRIBUTIONS OF MESO-COMPOSITIONS

    • 摘要: 花岗岩是一种由石英、长石和黑云母等细观组分组成的非均质岩石, 其变形破坏过程取决于细观组分的分布与相互作用, 可以使用颗粒流模型来研究这种非均质性与岩石的宏细观关系。本文以甘肃北山花岗岩为例, 通过提取单轴压缩试验视频中的单帧图像, 将矿物识别传统方法与图像灰度阈值分割技术结合起来、得到了不同细观组分的实际位置, 使用二维颗粒流代码(PFC2D)中的代码包FishTank生成了细观颗粒的初始分布, 根据实际位置和具体类型确定初始分布中的颗粒类型, 使用平行连接模型来表征细观组分颗粒之间的相互作用, 使用宏观力学性质参数来标定细观力学性质参数, 建立了基于实际分布的花岗岩颗粒流模型, 讨论了试件变形破坏过程中裂隙和力链的演变过程。结果表明, 颗粒流模拟所得花岗岩宏观力学性质参数(峰值应力、弹性模量、泊松比)与试验结果的相对误差平方和达到了可靠性要求, 花岗岩破坏过程中主要裂隙延伸方向平行于压应力方向, 裂隙主要分布于长石组分区域、以拉裂隙为主, 力链网络演变过程与岩石变形破坏过程基本一致。本文以细观组分实际分布为研究对象, 反映了岩石组成的本质特征, 对研究岩石宏细观关系、预测变形破坏过程都具有重要的 参考价值。

       

      Abstract: The granite is a heterogeneous rock with the deformation and failure mechanism depending on the distributions and interactions of the meso compositions, including feldspar, quartz and biotite. The heterogeneity and macro-meso relation could be considered using the particle flow model in the current study. The test video images of the granite from Beishan were photographed during the uniaxial test. The conventional mineral recognition method and the grayscale threshold segmentation were then used together to get the actual distribution of each compositions in a frame extracted from the video images. The initial distributions were generated using the package FishTank of particle flow code in two-dimensions(PFC2D).The distribution of each composition was used to determine the types of particles in the initial locations. The interaction between compositions was characterized by the normal contact strengths between particles. The meso mechanical properties were determined by the macro mechanical properties. The particle flow model of granite based on the actual distributions was thereafter established. And the evolution of fissuring and force chain during the process of deformation and failure was discussed. It shows that the sum of squares of relative error between the simulated results and the actual ones is meet reliability requirements; the major fissuring generated in process of deformation and failure of granite was parallel to the direction of compressive stress; most of the fissuring was distributed in feldspar and was tensile fissuring; the evolvement of force chain network is in accordance with the process of deformation and failure of granite. The studied objects in the current study are the actual heterogeneous locations of the compositions in granite, it is reflect the substantive characteristics of petrographic composition and the presented results may be of great significance in investigating the macro-meso relations and forecast the process of deformation and failure for heterogeneous rock materials.

       

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