电渗加固软土地基界面电阻理论与试验研究

Theoretical and experimental studies on interfacial resistance of electro-osmotic consolidation for soft ground improvement

电渗法在软土地基加固、淤泥疏浚及重金属污染修复领域均有尝试性应用,但在电渗固结过程中黏土-电极界面电势损失较大,导致能耗较高。本研究从电化学角度出发,对黏土-电极界面反应过程进行分析,解释了界面电阻的产生机理。同时,结合界面电阻模型,采用金属电极(铜)和电动土工合成材料电极开展室内电渗试验,研究长期通电下界面电阻变化规律。研究结果表明:在长期持续通电情况下,界面电阻模型可用于分析界面电阻变化机理;通电初期总界面电阻受阴极界面电阻影响较大,随着通电的进行逐渐变为受阳极电阻控制。界面电阻是电渗排水效率的重要影响因素,建议在工程中对界面电阻进行监测并作为电渗设计的控制指标。

The electro-osmosis has been applied experimentally in the fields of ground improvement,silt dredging and heavy metal pollution remediation.However,the potential loss at the clay-electrode interface during electro-osmosis consolidation is high,resulting in high energy consumption.In this study,the reaction process at the clay-electrode interface is analyzed from an electrochemical perspective to explain the mechanism of interfacial resistance.Based on the interfacial resistance model,the indoor electro-osmotic tests are carried out using metallic electrodes(copper) and electrodes of electro-kinetic geosynthetic to study the changes in the interface resistance under long-term energization.The results show that the interfacial resistance model can be used to analyze the mechanism of interfacial resistance change under long-term electroosmotic conditions.The total interfacial resistance is influenced by the cathodic interfacial resistance at the early stage of energization,and at the later stage of electroosmosis,it is more influenced by the anode resistance.The interfacial resistance is an important influence on the efficiency of electro-osmotic drainage.Therefore,it should be monitored and used as a control index for electro-osmotic design in the project.