软土路基微结构扫描电镜图像的分形

根据分形模型的构造方法,提出了用于描述软土孔隙变化的孔隙度分维、孔隙分布分维和孔隙边缘形状分维,并以珠江三角洲地区某高速公路软土路基加固为例,用分形维数对土体扫描电镜(SEM)图像进行分析。研究发现,加固后3种分形维数均有不同程度降低,表明加固后孔隙的分布面积减小,结构单元体之间排列紧密,孔隙尺寸分布趋于均匀,孔隙边缘形状变得规整光滑。结果表明,软土中孔隙分布及形状具有分形特征,不同的分形维数,可以从不同角度反映土体的加固效果及力学特性变化。

Fractal approach on soft soil subgrade microstructure SEM image

Based on the creation of fractal model,three kinds dimensions,such as porosity density dimension,porosity distribution dimension and porosity edge shape dimension,are proposed to describe the variations of porosity in soft soil microstructure SEM image.Taking the highway subgrade reinforcement in Zhujiang Delta as an example,this paper analyzes the soil SEM image with fractal dimensions.According to the analysis,these dimensions of the reinforced soft soil diminish in different degrees,which indicate that the distribution area of porosity decreases,the structure units array more tightly,the porosity size distribution becomes uniform,and the edge of porosity turns smooth.All of these results disclose that the distribution and the shape of porosity have fractal feature.Different fractal dimensions show the reinforced effectiveness and the feature variations of soil mass from different views.1 tab,4 figs,15 refs.