利用自主研发的试验装置,进行电渗法与密闭式真空预压法联合加固软黏土地基的室内模型试验,通过实时监测真空预压膜下真空度、塑料排水板中真空度以及土体出流量变化情况,并对电渗法中电流强度、电势变化进行量测。试验结束后,量测土体表面沉降值,并对不同部位的土体进行十字板抗剪强度、含水率、土体p H值、土体电导率试验。试验结果表明:真空预压–电渗联合加固软黏土地基比真空预压单独加固软黏土地基处理效果好;真空预压加固软黏土地基的处理效果的好坏取决于膜下真空度与塑料排水板中真空度的大小;在联合作用下,真空预压与电渗法能够相互促进,显示出较好的契合度,阳极区总电阻增加值大于阴极区,阴极区总电阻的增加主要与阴极区土体成分变化及土体含水率变化有关,阳极区总电阻的增加主要与界面电阻以及阳极区土体的水分减少有关。针对温州地区吹填软黏土,塑料排水板与金属电极共同作用构成的电渗阴极能够有效实现水分的汇集与排出,加固效果十分显著。
An electro-osmosis combined with closed vacuum preloading indoor model test was conducted on the soft clay using a self-developed apparatus. Vacuum pressure under the sealing membrane and the plastic drainage board,the change of soil drainage,current intensity and potential were monitored in real-time. After the test,surface subsidence,vane shear strength,moisture content,p H valves of soil and conductivity were measured in the different parts of the soil. The results show that the treatment effect of the combined method is better than that of vacuum preloading alone. Under the combined application,vacuum preloading and electro-osmosis can promote each other. The increase value in anodic resistance is greater than that in cathodic region. The increase of cathodic resistance is primarily related to the changes in soil composition and moisture,and the increase of anodic resistance is primarily related to the increase of interface resistance and the decrease of moisture content. The water can be discharge effectively and the reinforcement effect is improved significantly through the electroosmosis cathode constituted with plastic drain board and metal electrodes.