应用分形理论研究饱和土壤渗透率

Applying Fractal Theory to Study Permeability of Saturated Soil

基于多孔介质分形理论,开展饱和土壤一维土柱渗流实验;探讨不同土壤饱和渗透率。实验选取不同颗粒大小的石英砂,配制5种实验土样并测定其粒径分布特征,采用达西装置测定不同土壤的渗透系数。实验结果显示:土壤体积分形维数D与土壤平均粒径MZ呈线性关系:D=C MZ+E;土壤渗透率k与其D呈对数函数关系:k=[A ln D+B](ρg/μ); k与D关系函数为经验公式,A、B两个经验参数的物理意义还需进一步探索。

The permeability of saturated soil is one of the important parameters for analyzing water flow and its material migration.One of the key factors affecting the permeability of saturated soil is the structural characteristics of the soil itself.Based on the fractal theory of porous media,a one-dimensional soil column seepage test for saturated soil is carried out in this paper.The experiment selected quartz sands with different particle sizes,and 5 experimental soil samples.The particle size distribution,permeability coefficient determination of different soils are measured using Darcy device.Experimental results show that:(1)The soil volume fractal dimension(D)has a linear relationship with the average soil particle size(Mz):D=C MZ+E;(2)Soil permeability(k)and its D have a logarithmic function:k=[A ln D+B](ρg/μ);(3)The empirical relationship between k and D is an empirical formula,and the physical meaning of two empirical parameters of A and B should be further explored.