电势作用下非饱和黄土水分迁移试验研究

Experimental Research on Unsaturated Loess Moisture Migratio under the Action of Electric Potential

采用自制的试验装置,基于电渗法试验,笔者对以下问题进行了探究:电渗作用能否导致非饱和黄土土体含水量降低?电势、土体含水量水平等因素对非饱和黄土电渗结果有何影响?非饱和黄土电渗时效如何评价?试验结果表明:在电渗作用下,非饱和黄土试样内的水分从正极迁移向负极,达到降低正极区含水量的目的,说明电渗作用能使非饱和黄土土体内的含水量降低;电渗过程中,沿电渗方向的电势大致呈线性分布,电渗电势越大,降低正极区土体含水量的效果越好;由于正极水化反应增强和土体电阻发热量引起了水分耗损,高电势作用下土体内的含水量水平低于低电势作用土样。在试验土样含水量范围,土体初始含水量越低,电渗作用下正极区土体含水量降低值越大,但初始含水量差异引起的正极区含水量变化的差异性不大。电渗作用下非饱和黄土的水分迁移前期快,后期慢,随着电渗时间的延长,正极区含水量会进一步降低,负极区的含水量会进一步升高。

One-dimensional With the application of laboratory tests of electroosmosis a self-made test device,a serious of problems were investigated,such as： whether unsaturated loess soil moisture content decreased under electroosmosis？ What effect do electric potential,moisture content of soil and other factors have on the result of unsaturated loess electroosmosis？ How to evaluate the unsaturated loess electroosmosis aging？ Test results show that under the action of electroosmosis,the moisture content of unsaturated loess migrates from the anode to the cathode,which achieve the purpose of reducing the moisture content of soil of the anode region,indicating that electroosmosis make the moisture content of unsaturated loess soil decreased; on the process of electroosmotic,along the direction of the electroosmotic electric potential being roughly linear distribution,with increasing electroosmotic electric potential,the soil moisture content in the cathode area is lower; Since the enhancement of the anode hydration reaction and heat resistance of soil leading to water loss,the moisture content of soil on the action of high electric potential is less than that on the low electric potential. In the range of the moisture content of test samples,the lower initial moisture content of soil lead the greater lower value of moisture content of anode region of soil on the action of electroosmosis,but the anode region moisture difference caused by the initial moisture content difference is not obvious; unsaturated loess moisture migration is rapid early but slow in later stage. With the extension of the electroosmotic time,the moisture content of soil on the anode region will be further reduced,and that on the cathode region will be further increased.