含水率对亲水-斥水复合土压缩特性的研究

Analysis of the influence of water content on compression properties of hydrophilic and water-repellent composite soil

高塑性砂-黏土混合物通常被用作土坝的防渗芯及部分农业所需栽培土及少量工程换填土,故对云南省当地红黏土及砂土的混合物(亲水-斥水复合土)采用WG-4型固结仪进行侧限压缩试验,得到了压实亲水-斥水复合土孔隙比、变形量和含水率的关系以及改变土的性质后对基本物理指标及变形量的影响。结果表明:孔隙比、变形量会随着含水量的增加而增大,当含水率接近最优含水率时,土体越易被压实。另外,改变土体的亲水性和斥水性对侧限压缩试验来说没太大影响,但会改变一些物理特性,如在红黏土中加入斥水剂或在红黏土中掺30%的砂土后,它们的界限含水率减小了,最优含水率也相对减小了。

Highly plastic sand-clay mixtures are commonly used as impermeable cores for earth dams,part of the cultivation soil for agriculture and a small amount of engineering replacement soil.In this paper,a confined compression test is carried out on the mixture of local red clay and sand(hydrophilic and water-repellent composite soil)in Yunnan Province by WG-4consolidation estimator,and the relationship between the pore ratio,the deformation and water content of the compacted hydrophilic and water-repellent composite soil,as well as the influence of the changed soil properties on the basic physical indexes and deformation are obtained.The results show that the pore ratio and deformation increase with the increase of water content.When the water content is close to the optimal water content,the soil is easier to be compacted.In addition,changing the hydrophilicity and water-repellant of soil has little influence on the confined compression test,but will change some physical properties.For example,for red clay with repulsive agent and red clay mixed with 30%sand,their water content limit decreases,and the optimal water content is also relatively reduced.