电极反转模式下反转电压对电渗影响试验研究

Experimental study on the effect of reversal voltage to electro-osmosis using polarity reversal method

电渗法可以加快低渗透性软土排水固结,被视为一项极有前景的地基处理技术,在电渗法处理软土地基时,常采用电极反转的通电方案。为了研究电极反转通电时反转电压对电渗加固的影响,开展不同反转电压下电渗法加固软土地基室内一维模型试验,实测电渗过程中的排水量、排水速率、电流电压值,以及试验结束后土体含水率分布情况。试验结果表明:在本文试验条件下,短时间反转通电会对电渗排水效果产生不同影响,且能使电渗加固效果更为均匀;随反转电压的增加,电渗排水量先增加后减小,过高的反转电压会对电渗效果起抑制作用;反转通电主要通过影响电流对电渗产生作用,恢复正向通电后土体电流急剧提升,电极反转产生积极影响,而恢复正向通电后土体电流突降时电极反转抑制排水。本文试验证明了在合适的反转参数下,电极反转不仅能使土体加固效果均匀,还可以促进排水,提高电渗效率。

Electro-osmosis can accelerate the consolidation of low permeability soft soils and is regarded as an extremely promising foundation treatment technology.Electro-osmosis often uses an energized scheme with polarity reversal.In order to study the effect of reversal voltage on electro-osmotic using polarity reversal method,one-dimensional laboratory tests of electro-osmosis under different reversal voltages were carried out.The drainage volume,drainage rate,and current and voltage values during the electro-osmosis process were measured.The distribution of water content at the end of the test was also monitored.The test results show that,under the experimental conditions of this paper,the short time polarity reversal method will have different effects on the drainage volume and can make the soil more uniform.With the increase of reversal voltage,the volume of drainage first increases and then decreases.High reversal voltage will inhibit the effect of electroosmosis,and polarity reversal produces an effect mainly by influencing the current.The polarity reversal method has a positive effect when the current rises sharply after restoring forward energization.And when the soil current drops suddenly after restoring forward energization,the polarity reversal inhibits drainage.The experiment in this paper proves that with suitable reversal parameters,polartiy reversal can not only improve soil homogeneous,but also promote drainage and improve electro-osmosis efficiency.