以衡水地面沉降漏斗中心分层标土柱黏土试样的环境电镜扫描图像为研究对象,采用分形理论和ERDAS软件的图像处理技术,求取了华北平原地面沉降典型区第四系黏土微观孔隙分布的分维数,得出华北平原第四系黏土微观孔隙分布分维值随埋深的增大呈现总体减小、局部增减交替的特征。并结合黏土试样的空间位置、密度值、矿物组分、化学成分及地下水等因素,探讨了华北平原第四系黏土微观孔隙分形特征的成因机理。
The land subsidence in the North China Plain (NCP) is one of the most typical environmental geological problems on the planet. The Quaternary sediments in the NCP are composed of clay, coarse sand, fine sand and silty sand. The soil column of Quaternary sediments is collected in Hengshui land subsidence cone, one cone of the NCP, and the SEM pictures are taken for the typical clay samples. Then the software ERDAS is used to calculate the microcosmic pore valid perimeters and valid area of the SEM pictures to obtain the microcosmic pore fractal dimension. The analysis of the fractal characteristics and the clay surroundings leads to the conclusion that there exists some relation between the microcosmic pore fractal dimension and the clay surroundings. This paper also presents another way to study the microcosmic pore fractal dimension of soil.