基于数字图像处理技术的砂土颗粒级配分析研究

砂土颗粒级配是影响砂土工程性质的重要参数之一，传统的颗分试验方法由于试验原理不同而具有不同的适用范 围。为更加方便、准确地获取砂土颗粒级配，提出了一种基于数字图像处理技术来获取SEM照片中的砂颗粒粒径参数及级 配特征的新方法。将准备好的砂土样品打磨成薄片放在扫描电镜下拍照，然后利用Photoshop软件对照片进行拼接，并采用 自主研发的SMAS数字图像分析系统对拼接好的照片进行定量分析处理，获取样品的微观结构参数，将获得的“土颗粒等 效直径”和“土颗粒面积”分别等效为实际土颗粒粒径和土颗粒质量，进而换算得到砂土的颗粒级配曲线；然后将通过数 字图像技术获得的砂土颗粒级配曲线与通过传统筛分法和激光粒度分析法得到的颗粒级配曲线进行对比，验证了提出的数 字图像处理方法的有效性和可靠性，同时分析了两种方法之间存在的差异及其原因，并对数字图像处理方法和传统颗分方 法各自的优缺点进行了讨论。

Gradation Analysis of Sand Particles Based on Digital Image Processing Technology

Sand particle grading is one of the important parameters affecting the engineering properties of sand. The traditional grain size analysis methods have different application range due to different test principles. In order to obtain sand particle gradation more conveniently and accurately, a new method based on digital image processing technology to obtain sand particle size parameters and grading characteristics in SEM photographs is proposed. The prepared sand samples are polished into thin slices and photographed under a scanning electron microscope. Then the photos are stitched by Photoshop software, and the self-developed SMAS digital image analysis system is used to quantitatively analyze the stitched photo to obtain the stuctural parameters of microscopic samples. The obtained“equivalent diameter of soil particles”and“area of soil particles”are respectively equivalent to the actual soil particle size and soil particle quality, which can be converted to the particle gradation curve of sand. The obtained sand particle gradation curve is compared with the particle grading curve obtained by the traditional sieving method and laser particle size analysis method. The validity and reliability of the proposed digital image processing method are verified. The differences between digital image processing methods and traditional grain size analysis methods are analyzed, and their advantages as well as disadvantages are discussed.