软土微观结构表面起伏的三维可视化及分形维数的计算  

3D Visualization and Fractal Dimension of Soft Clay's Microstructure Surface Undulation

作　　者：张先伟[1,2] 王常明[1] 马栋和[1] 

机构地区：[1]吉林大学建设工程学院,吉林长春130000 [2]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071

出　　处：《应用基础与工程科学学报》2012年第1期103-112,共10页Journal of Basic Science and Engineering

基　　金：国家自然科学基金项目(40572153)

摘　　要：结构表面的起伏程度是衡量土微观结构的重要特征,目前研究多是二维定性与定量的分析方法,难以全面、真实地反映土的结构表面起伏情况.通过对青岛、广州和中山地区原状软土扫描电镜照相,将SEM图像的灰度设为结构表面至成像表面的距离,根据相互垂直剖面的微观孔隙大小确定了灰度与像素之间转换关系,进而获得软土的三维微观信息,将其导入三维地学软件实现了微观结构表面的三维可视化.该方法操作简单,通过可视化操作可以更直观观察土的结构形态,获得的信息量远远超过二维图像本身.通过改进后的投影覆盖法,提出了一个计算土的结构表面起伏真实分形维数Ds(2≤Ds<3)的方法,得到青岛软土的Ds大于广州软土和中山软土的Ds,说明青岛软土结构表面起伏最复杂.Microstructure surface undulation is an important characteristic to measure the soil microstructure,but the current studies are mostly qualitative and quantitative two-dimensional analysis, which difficult to comprehensively and veritably reflect the situation of soil microstructure surface undulation. Using the scanning electron microscope photograph of soft clay in Qingdao, Guangzhou, Zhongshan regions, setting SEM image＇s gray value as the distance which from micro-structured surface to imaging surface, and according to characteristics of the micro-pore vertical profile can determine the conversion relationship between gray value and pixel value, thus obtain three-dimensional microscopic information of soft soil, import into 3D geological software that can achieved microstructure surface 3D visualization. This method is simple to implement, through structure of the soft clay, the visualization operations we can more intuitively observe the amount of information obtained far exceeds the two-dimensional image itself. Through improved projective covering method, proposed a method that how to calculate the true fractal dimension D, of microstructure surface undulation （ 2 ≤ Ds 〈 3 ）, obtaining the soft clay D, in that the soft clay in Qingdao Qingdao are greater than Guangzhou and Zhongshan＇s, this shows has the most complex microstructure surface undulation.

关 键 词：软土 微观结构 三维可视化 结构表面起伏 分形维数 

分 类 号：TU447[建筑科学—岩土工程]