考虑微观结构的非饱和渗透系数计算公式

The Equations of Unsaturated Permeability Considering the Microstructur

摘要:

分维理论是预测非饱和渗透系数的一种常用方法。在对有侧限条件下高庙子膨润土的非饱和渗透系数的试验结果分析后，发现分维理论并不适用，其缺陷在于不能够反映膨润土这种特殊粘土在水化过程中的微观结构变化。因为膨润土是一种纳米材料，其小孔隙和大孔隙分布在水化过程中都会发生变化，而一般性粘土和砂土没有这种特殊的物理化学特性。结合Kozeny-Carman关于多孔介质的半经验公式，提出了半经验-半理论的考虑微结构的膨润土的非饱和渗透系数计算公式。在对高庙子膨润土的扫描电镜试验和压汞试验资料分析的基础上，定性验证了所提出公

Abstract:

The fractal theory is a common method to predict the unsaturated permeability. But the theory can not be used in the computing of unsaturated permeability of Gaomiaozi bentonite in confined condition. The microstructure of bentonite changed a lot in the saturation process, and this phenomenon can not be reflected in the equations of fractal theory. The micro pores and macro pores of bentonite changed a lot in the saturation process which is different with the common sand or clay. With the consideration of Kozeny-Carman equation, a semiempirical-semitheorytical unsaturated permeability equation considering the microstructure of bentonite has been proposed based on the SEM test and MIP test of Gaomiaozi bentonite. The new equation was used in the analysis of unsaturated permeability of Gaomiaozi bentonite in the confined condition.