陈陶, 徐金明. 2017: 温度和压强对花岗岩中矿物微观物理力学特性的影响. 工程地质学报, 25(6): 1474-1481. DOI: 10.13544/j.cnki.jeg.2017.06.010
    引用本文: 陈陶, 徐金明. 2017: 温度和压强对花岗岩中矿物微观物理力学特性的影响. 工程地质学报, 25(6): 1474-1481. DOI: 10.13544/j.cnki.jeg.2017.06.010
    CHEN Tao, XU Jinming. 2017: EFFECTS OF TEMPERATURE AND PRESSURE ON MICROSCOPIC PHYSICAL AND MECHANICAL FEATURES OF MINERALS IN GRANITE. JOURNAL OF ENGINEERING GEOLOGY, 25(6): 1474-1481. DOI: 10.13544/j.cnki.jeg.2017.06.010
    Citation: CHEN Tao, XU Jinming. 2017: EFFECTS OF TEMPERATURE AND PRESSURE ON MICROSCOPIC PHYSICAL AND MECHANICAL FEATURES OF MINERALS IN GRANITE. JOURNAL OF ENGINEERING GEOLOGY, 25(6): 1474-1481. DOI: 10.13544/j.cnki.jeg.2017.06.010

    温度和压强对花岗岩中矿物微观物理力学特性的影响

    EFFECTS OF TEMPERATURE AND PRESSURE ON MICROSCOPIC PHYSICAL AND MECHANICAL FEATURES OF MINERALS IN GRANITE

    • 摘要: 岩石工程性质取决于岩石中不同矿物的微观特征,本次研究将从微观角度计算北山花岗岩中主要矿物(石英、黑云母和钠长石)的物理性质和力学性质。矿物的微观物理性质使用体积和密度来表征,矿物的微观力学性质使用杨氏模量和泊松比来表征;矿物的初始晶体结构、初始晶胞参数、单晶胞模型和超晶胞模型使用公开数据库获得;矿物晶胞的稳定构象由几何优化方法来实现;使用分子力学模拟,得到了不同矿物稳定构象的微观物理性质参数和微观力学性质参数;使用分子动力学模拟,分析了温度和压强对这些微观物理力学性质参数的影响。结果表明,花岗岩的3种主要矿物中,晶胞体积大小顺序是钠长石、黑云母、石英,晶胞密度大小顺序是黑云母、石英、钠长石;石英的杨氏模量为161.70~168.78GPa、泊松比为0.25,黑云母的杨氏模量为164.85~579.93GPa、泊松比为0.16~0.31,钠长石的杨氏模量为110.72~112.49GPa、泊松比为0.27;压强为0.0001GPa、温度从300K变化到500K时,石英晶胞体积增大0.17%、密度减小0.15%、杨氏模量和泊松比没有明显变化,黑云母晶胞体积增大0.24%、密度减小0.26%、杨氏模量增大140.55%、泊松比减小26.92%,钠长石晶胞体积减小3.76%、密度增大3.91%、杨氏模量增大319.71%、泊松比减小7.41%;温度为298K、压强从0.010GPa变化到0.020GPa时,石英晶胞体积、密度、杨氏模量和泊松比没有明显变化,黑云母晶胞体积和密度没有明显变化、杨氏模量增大53.79%、泊松比减小23.81%,钠长石晶胞体积和密度没有明显变化、杨氏模量减小36.24%、泊松比增大29.41%。研究结果对分析岩石宏观物理力学特性的微观机制具有一定的参考价值。

       

      Abstract: The engineering properties of a rock are much dependent on the microscopic features of the minerals comprising the rock. The physical and mechanical features of various minerals(i.e. quartz, biotite and albite) in Beishan granite are investigated in a micro scale in the current study. The microscopic physical features of the minerals are characterized by volume and density, while the microscopic mechanical features of the minerals are characterized by Young modulus and Poisson ratio. The open database is used to obtain the initial crystal structure, initial cell parameters, and the unit and super cells of the minerals. The stable configurations of the mineral cells are obtained using the geometry optimization. The microscopic physical and mechanical parameters of the stable configurations are then computed using the molecular mechanics simulation. The effects of temperature and pressure on these microscopic physical and mechanical parameters are furthermore examined using the molecular dynamics simulation. It shows that in the main minerals included in granite, the great-small sequence of the cell volume is albite, biotite, and quartz, while that of the cell density is biotite, quartz, and albite. The Young modulus values of quartz, biotite and albite are 161.70 to 168.78GPa, 164.85 to 579.93GPa and 110.72 to 112.49GPa, respectively. The Poisson ratio values of quartz, biotite and albite are 0.25, 0.16 to 0.31, and 0.27, respectively. When the temperature changes from 300K to 500K under the pressure of 100kPa, the volume increases 0.17% and the density decreases 0.15%with no obvious changes in the Young modulus and Poisson's ratio for the quartz cell; the volume increases 0.24% and the density decreases 0.26%with the Young modulus increased 140.55% and the Poisson's ratio decreased 26.92%for the biotite cell; and the volume decreases 3.76% and the density increases 3.91%with the Young modulus increased 319.71% and the Poisson's ratio decreased 7.41%for the albite cell. When the pressure changes from 0.010 to 0.020GPa at the temperature of 298 K, the volume, density, Young modulus and Poisson's ratio have no obvious changes for the quartz cell; the volume and density have no obvious changes with the Young modulus increased 53.79% and the Poisson's ratio decreased 23.81%for the biotite cell; and the volume and density have no obvious changes with the Young modulus decreased 36.24% and the Poisson's ratio increased 29.41%for the albite cell. These theoretical results can be referable in analyzing the macroscopic physical and mechanical properties of the rock materials in a micro scale.

       

    /

    返回文章
    返回