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目的:建立一种较为快速和快速确定非均匀岩土材料渗透系数的方法。创新点:建立了一种可以从图像到数值模型的数字图像方法:通过拍照、CT等手段获取岩土材料的图像,进而通过数值分析确定等效参数。方法:1.将采集到彩色图像从RGB空间转化到HSI空间,选取识别度较高的空间进行二值化处理;2.获取二值化图像后采用邻域标记算法标记,结合本文提出的算法提取边界(图9和10);3.结合边界修正算法对锯齿状边界进行修正(图11);4.确定表征细观几何模型(图12和表1);5.绘制网格开展数值分析,确定宏观参数。结论:1.基于数值图像的非均匀岩土材料渗透系数确定方法可以较为准确地估算渗透系数,可以为工程设计提供初步依据。2.非均匀岩土材料具有明显的尺寸效应,随着尺寸增加,渗透率的变化逐渐趋于稳定;当材料视为岩石和土体的二元介质时,两种性质差异在10倍以内对宏观特性的影响较大,大于10倍之后影响减弱。3.岩土材料渗透率随着内部块石含量的增加而减小,但是内部块石的形态对渗透率也有一定的影响。
Objective: To establish a more rapid and rapid method to determine the permeability coefficient of heterogeneous geomaterials. Innovative point: A digital image method that can be used from image to numerical model is established. The image of geotechnical material is obtained by photographing and CT, and then the equivalent parameters are determined through numerical analysis. Methods: 1.Collected the color image from RGB space to HSI space, select the high degree of recognition space for binary processing; 2.Binary image obtained after the use of neighborhood marking algorithm tag, combined with the proposed algorithm (Figure 9 and 10); 3. Correction of the jagged boundary with the boundary correction algorithm (Figure 11); 4. Determine the characterization of the meso-geometry model (Figure 12 and Table 1); 5. Draw a grid for numerical analysis , Determine the macro parameters. Conclusion: 1.The method of determining the permeability coefficient of heterogeneous geomaterials based on numerical images can accurately estimate the permeability coefficient, which can provide a preliminary basis for engineering design. 2. Inhomogeneous geomaterials have obvious size effect. As the size increases, the permeability changes gradually stabilize. When the material is considered as binary medium of rock and soil, the difference between the two properties is within 10 times Macro-characteristics of the larger impact is greater than 10 times weakened. 3. The permeability of geomaterials decreases with the increase of the content of intrablocks, but the shape of intrablocks also has some influence on the permeability.