土体孔隙分形模型及其与土体渗透性关系的研究

土体颗粒和孔隙分布直接影响土体渗透性大小。文章引入分形几何理论,基于土颗粒粒度的分维系数和球形土颗粒的假设,确定了单位体积土体中土颗粒的总数以及孔隙的总表面积,进而建立土体孔隙比表面积分形模型。该模型包括的四个参数可由实验方法确定。实例分析结果证明,土体的渗透系数随孔隙比表面积增大而逐渐减小,这与渗流分析结果一致。验证了模型的合理性和可行性,为土体渗透性的研究提供了一种新的方法。

Study of Soil Mass Pore Fractal Model and Its Relation to Soil Mass Permeability

The distribution of soil grains and pores in soil mass directly influence the permeability of soil mass.In this paper the theory of fractal geometry was introduced,and the total number of soil grains and the total surface area of pores per unit volume of soil mass were calculated based on the soil grain fractal coefficient and the hypothesis,in which the soil grain was assumed to be spherical,and then the pore surface area-volume ratio fractal model of soil mass was established.The four parameters involved in the model can be determined by experiment.The example analysis result show that the permeability coefficient of the soil mass decreases with the increase of its pore surface area-volume ratio.It is consistent with the seepage analysis result.The model proved to be rational and feasible,and has provided a new method for study of permeability of soil mass.