Abstract

Electro-osmotic consolidation combined with vacuum preloading is a potential technology to dewater the soft soils and slurry. The anode condition has a significant effect on dewatering efficiency during operation, which is not adequately addressed. In this study, laboratory tests were conducted to study the effect of different boundary conditions of anode on the soil-improvement result using the combination of electro-osmotic consolidation and vacuum preloading, then to obtain the best combination mode. During the physical modeling tests, the soil mass was treated by vacuum preloading first and then further processed by the combined method. Three model tests were conducted to study the effect of different vacuum conditions on electrode, while CaCl₂ solutions were injected at the anode in another two tests to study the effect of the electro-osmotic chemical treatment. The discharge of water and electrical current were measured during the tests, and the soil strength were measured after the implementation of the tests. The results indicated that the combined method was more effective to remove pore water from the soil mass compared with the traditional vacuum preloading. Although the vacuum preloading and electro-osmosis drove the water flow in the opposite direction near the anode, the vacuum pressure applied on the anode prevented the soil cracks, which increased electrical current obviously and removed 15% more pore water. The injection of CaCl₂ solution at the anode showed slight effect on dewatering process, however, the bearing capacity was increased significantly.

摘要

电渗固结与真空预压相结合是软土和泥浆脱水的一种潜在技术。阳极条件对运行期间的脱水效率有显着影响，但尚未得到充分解决。本研究通过室内试验研究了不同阳极边界条件对电渗固结与真空预压相结合的土壤改良效果的影响，从而获得最佳组合模式。在物理建模试验中，土体先进行真空预压处理，再采用组合法进一步处理。进行了三个模型试验，研究了不同真空条件对电极的影响，而 CaCl ₂在另外两个测试中在阳极注入溶液以研究电渗化学处理的效果。在试验过程中测量了水和电流的排放量，并在试验实施后测量了土壤强度。结果表明，与传统的真空预压法相比，联合法去除土体中的孔隙水更为有效。虽然真空预压和电渗驱动阳极附近的水流向相反方向流动，但施加在阳极上的真空压力防止了土壤裂缝，电流明显增加，孔隙水多去除了15%。_{CaCl 2}的注入阳极溶液对脱水过程影响不大，但承载能力显着提高。