X-ray CT analysis of pore structure in sand
X-ray CT analysis of pore structure in sand
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DOI：
10.5194/se-7-929-2016
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发表时间：
2016-06
期刊：
影响因子：
3.4
通讯作者：
T. Mukunoki;Y. Miyata;K. Mikami;Erika Shiota
中科院分区：
文献类型：
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作者：
T. Mukunoki;Y. Miyata;K. Mikami;Erika Shiota
抽象的。微聚焦X射线计算机断层扫描（CT）设备的发展使数字成像分析在孔隙尺度。这些设备的应用是不同的土壤力学，岩土工程和地质环境工程，石油工程，农业工程。特别是，在多孔介质中的孔隙空间的成像有助于单相和多相流或污染物通过孔隙结构的三维图像数据传输的数值模拟。这些获得的结果受到孔径的影响，因此，有必要验证用于图像分析的图像预处理，并验证从CT图像数据获得的孔径。此外，在代表性单元体（REV）中产生物理参数和确定REV的尺寸是有意义的。本文描述了图像处理和分析的基本方法，并讨论了丰浦砂的物理特性，以验证基于REV定义的图像分析。在获得验证结果的基础上，可以进行孔径分析，并通过与实验工作和图像分析的比较来验证。根据杨-拉普拉斯定律和排水过程的保水试验推导出孔径。本文将以往的研究结果与本研究中提出的多孔孔径法（称为体素逾渗法）进行了比较。此外，REV的局限性，孔径的定义，和有效性的VPM的孔径评估进行了讨论。
Abstract. The development of microfocused X-ray computed tomography (CT) devices enables digital imaging analysis at the pore scale. The applications of these devices are diverse in soil mechanics, geotechnical and geoenvironmental engineering, petroleum engineering, and agricultural engineering. In particular, the imaging of the pore space in porous media has contributed to numerical simulations for single-phase and multiphase flows or contaminant transport through the pore structure as three-dimensional image data. These obtained results are affected by the pore diameter; therefore, it is necessary to verify the image preprocessing for the image analysis and to validate the pore diameters obtained from the CT image data. Moreover, it is meaningful to produce the physical parameters in a representative element volume (REV) and significant to define the dimension of the REV. This paper describes the underlying method of image processing and analysis and discusses the physical properties of Toyoura sand for the verification of the image analysis based on the definition of the REV. On the basis of the obtained verification results, a pore-diameter analysis can be conducted and validated by a comparison with the experimental work and image analysis. The pore diameter is deduced from Young–Laplace's law and a water retention test for the drainage process. The results from previous study and perforated-pore diameter originally proposed in this study, called the voxel-percolation method (VPM), are compared in this paper. In addition, the limitations of the REV, the definition of the pore diameter, and the effectiveness of the VPM for an assessment of the pore diameter are discussed.