土体微观结构研究很早就建立了三维空间的分形模型,但分形维数计算所需参数很难由常规土工试验得到,限制了分形理论在土体研究中的应用。基于陕西定边与甘肃兰州原状土样的扫描电镜(SEM)试验,提出了三维化处理与三角形网格原理联合方法,可以得到土体颗粒(孔隙)不同测量尺度对应的表面积与体积计算值,由此实现分形维数的计算,并通过分形理论在土水特征中的应用验证了方法的有效性与可靠性。另外,三维化处理还可获取视孔隙率、比面等土体微观结构参数,可以作为土体微观结构定量分析研究的新途径。
Abstract
Fractal three-dimensional model has long been used to study soil microstructure. However, the acquisition of parameters necessary for calculating the fractal dimension through conventional geotechnical tests poses challenges, thereby limiting the utilization of fractal theory in soil research. To address this issue, a combined approach integrating three-dimensional processing and triangular grid principle is proposed in this study based on the scanning electron microscope (SEM) testing of undisturbed soil samples collected from Dingbian, Shaanxi Province, and Lanzhou, Gansu Province. This approach enables the calculation of surface area and volume values corresponding to various measurement scales of soil particles (or pores), facilitating the determination of fractal dimensions. The effectiveness and reliability of the proposed method are validated by applying fractal theory to analyzing soil-water characteristics. Moreover, the three-dimensional processing technique allows for the determination of other soil microstructure parameters, such as apparent porosity and specific surface area. Consequently, it can be regarded as a novel method for quantitatively investigating soil microstructure.
关键词
扫描电镜(SEM) /
微观结构 /
三维分析 /
分形维数
Key words
scanning electron microscope(SEM) /
microstructure /
three-dimensional analysis /
fractal dimension
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