细粒土粒径与物理特性关系的分形特征研究

Study on Fractal Features of Relationship between Fine Grained Soil Grain Size and Physical Property

以某矿区原状土为研究对象,针对细粒土颗粒结构的复杂性和不规则性,基于分形理论,通过颗粒分析、渗透试验和界限含水率试验,建立了细粒土粒度分形维数与不均匀系数、渗透系数及界限含水率的相关关系,从而揭示了这一类土粒度分维的物理意义。试验研究表明:土的颗粒级配越好,分维越大,不均匀系数就越大,水通过孔隙的能力变弱,渗透系数则越小。当土分维数小于某一数值时,土的界限含水率随分维值的增大而减小;分维大于这一数值时,各界限含水率指标又与分维值呈正相关关系。研究结果为该地区这一类细粒土的工程特性提供较好的研究思路和理论支持。

Taking the undisturbed soil in a coalmine area as subject investigated,in allusion to fine grained soil granular structure complexity and irregularity,based on fractal theory,through grain size analysis,permeability test and limit moisture content test,established correlativity between fine grained soil grain size fractal dimension and nonuniformity coefficient,permeability coefficient and limit moisture content,thus revealed grain size fractal physical significance of this kind of soil. The experimental study has shown that the better the soil grain size distribution,the larger the fractal dimension,and the larger the nonuniformity coefficient; the weaker the water pass through pores ability,the smaller the permeability coefficient. When soil fractal dimension is less than a certain value,soil limit moisture content decreasing along with fractal dimension increasing; if fractal dimension larger than that certain value,limit moisture contents present positive correlativity with fractal dimension. The study result has provided better research ideas and theoretical support for this kind of fine grained soil engineering features study.