Quantitative Analysis Of Micro-porosity Of Saturated Soft Clay And Its Fractal Description

The microstructure of soil includes the size and shape, spatial arrangement and distribution, contacting and concatenating way of soil grain, cluster, etc. of grains and pore. The microstructure of clay is an important factor in the determining of its engineering properties. In the article, the method of one-dimensional consolidation compression test was used on the soft clay saturatied and undisturbed. A scanning electron microscope (SEM) and digital image technology were used to study microstructure, in order to reveal the microstructure evolution mechanics in the consolidate process of soft clay. The fractal method is carried out to determine the fractal dimensiom of soil pore structure in micro scale, and the dependency relation between mechanic parameter, microstructure parameter and fractal dimension in the soft clay is established, to achieve the purpose of probing soil mechanics behavior. The article's main conclusions as follows:(1) Improving the soil's quantitative analysis capability and worked efficiency of SEM image excessively, and the microstructure parameter of soft clay can be meatured quickly by means of IPP technique.(2) The micro pore structure evolution regular in the consolidation deformation process of soft clay is: the pore size of soil clay drive to small, with the increase of consolidation pressure, range of size changes narrow, and the soli's consolidation process has specific regulating action to pore graduation.(3) The distributing way of soil's pore structure in two-dimensional space can be described as the dispersion system that pore distributes on the soil's tangent plane random, and which has apparent characters of Sierpinski fractal and Korcak fractal, its fractal dimension is measuring of pore to soil's tangent plane covering degree, and it shows the dimension of soil's porosity. Two kinds of fractal dimension are founction parameters to destribe the soil's pore structure.(4) In the consolidation deformation process of soft clay, consolidation pressure is bigger, and the porosity is lower, fine pore is more, fractal dimension is bigger, so fractal dimension could be used to describe the evolution course of micro pore structure in the process of soft clay's macrography distoration, thus a new data is supplied to forecast the consolidation deformation of soft clay.(5) Sierpinski fractal dimension has notable linear regression with soil clay's total porosity, consolidation pressure, compression deformation quantitation, and it could show the structure characteristic of soil clay; Korcak fractal dimension has notable linear regression with soil clay's pore number, consolidation pressure, compression deformation quantitation. The research findings of the article reveals microstructure fractal control mechanics of soft clay's macrography distoration.