砂土中黏粒含量对渗透性的影响

Influence of clay content on permeability of sandy soil

边坡滑动、地基液化等灾害现场土体中都含有一定含量的黏粒,且黏粒对砂土液化影响显著,因此研究不同黏粒对砂土力学特性的影响具有重要的工程意义。通过常水头渗透与变水头渗透试验,测定了纯砂及掺入不同黏粒后砂土的渗透系数。探讨了干密度、孔隙比与渗透系数之间的关系,分析了不同种类黏粒的砂粒间孔隙比对砂土渗透系数的影响。结果表明:黏粒含量越大,砂样的渗透系数越小;膨润土较高岭土对砂土渗透系数的影响更为显著;含黏粒的砂土砂粒间孔隙比随着黏粒含量的增加而增大。

In disastrous sites related to slope slide and liquefaction of foundation soil,sand always contains a certain amount of clay that has a significant effect on itself. Therefore,to study the engineering properties of sand mixed with clay is significant for safety of geotechnical engineering.The permeability coefficients of the pure sand and the sand mixed with different clay particles are obtained by the constant head test and the varying head test. The relationships between the dry density,the void ratio and the permeability coefficient of the specimens are discussed. The permeability coefficient of sand influenced by intergranular pores and void ratios of different types of cohesive particles is analyzed. The results show that the permeability coefficient of sand decreases with the increase of clay content. The influence of Bentonite on the permeability coefficient of sandy soil is more obvious than that of Kaolinite. The void ratio between sand grains increases with the increase of clay content. However,the void ratio between clay grains decreases with the increase of clay content.