土壤含盐量对电势作用下黄土水分迁移影响试验研究

Experimental research on effect of soil salinity in loess moisture migration under action of electric potential

为了研究电场作用下含盐非饱和黄土水分迁移特性,利用自制的室内一维试验装置,进行不同含盐量下非饱和黄土通电试验,监测试验过程中土体电流、电势变化及试验后含水量分布。研究结果表明:当初始含水量较低时,含盐量对非饱和黄土水分迁移效果影响明显,水分迁移效果随含盐量的增加先增大后减小,且含盐量在0.25%~0.50%时效果最显著。当初始含水量较高时,由于电极材料存在腐蚀,高含盐量对土体水分迁移的促进作用较差。在低初始含水量条件下,土体界面电阻随含盐量增加先减小后增大,有效电势随含盐量的增大先增大后减小。通电期间土体电阻率随含盐量的增加呈指数降低,且土体初始含水量和含盐量越高,土体电阻率越小。

In order to study the moisture migration characteristics of unsaturated loess with different soil salinity under electric field, the electrification test of unsaturated loess with different soil salinity was carried out by selfmade indoor one-dimensional test device. The soil current, the potential during the test and the distribution of water content after the test were analyzed. The results show that when the initial water content is low, the soil salinity has an obvious effect on the moisture migration of unsaturated loess. The effect of moisture migration increases first and then decreases with the increase of soil salinity, and the effect is most significant at 0.25%-0.50% of soil salinity. When the initial water content is high, the effect of high soil salinity on soil moisture migration is worse due to corrosion of the electrode material. Under the condition of low initial water content, the interface resistance of soil decreases first and then increases with the increase of salt content, and the effective potential increases first and then decreases with the increase of salt content. During the electrification period, the soil resistivity decreases exponentially with the increase of salt content, and the higher the initial water content and salt content of the soil are, the smaller the soil resistivity is.