使用氯化钙溶液加固淤泥质黏土的电渗试验研究

Experimental Research on the Effect of Using Calcium Chloride and Electroosmosis to Reinforce Silt Clay

采用自制电渗试验装置,针对武汉市淤泥质黏土进行电渗试验,探讨阳极处添加质量分数分别为0、5%、10%、15%氯化钙溶液对电渗加固效果的影响.通过监测电渗过程中各试验组电流和排水量随时间的变化,测定电渗前后土体的含水率、抗剪强度、孔隙比和微观结构变化,综合评价不同条件下土体的电渗固结效果.试验结果表明:在阳极添加氯化钙溶液可以缩短电渗固结时间,显著提高电渗法加固淤泥质黏土的效果,使土体微观结构变得更加致密,增强土体的抗剪强度;通过添加氯化钙溶液,阴极附近土体抗剪强度最大提高368.6%;氯化钙溶液浓度对电渗加固效果影响存在一个限值,本次试验为10%左右,超出该限值后,浓度的影响很小;氯化钙溶液的加入会加重电极腐蚀.

A series of laboratory experiments were performed in a customized apparatus to investigate the effect of using electroosmosis and calcium chloride with percentages of 0,5%,10%and 15%on reinforcing Wuhan silt clay.During the process of electrochemical treatment,the temporal evolution of electric current and drainage were monitored periodically.Also,the differences in moisture content,soil shear strength and microstructure before and after treatment were studied to assess the synchronous effect of electroosmosis and calcium chloride solution.The following conclusions can be drawn:injecting calcium chloride solution into anodic reservoir can significantly improve the efficiency of electroosmosis by shorting consolidation time and compacting soil microstructure,thus strengthening the properties of silt clay.Further,with injecting calcium chloride solution,the shear strength of cathodic soil increased by approximately 368.6%.However,there is a threshold value exists in the reinforcement effect,and the positive influence on reinforcing silt clay was negligible once the concentration of calcium chloride exceed 10%.Adding calcium chloride solution would induce severe electrode corrosion,simultaneously.