Experimental And Theoretic Study On Electro-osmosis Drainage And Consolidation Of Soft Clay

The traditional treating methods of soft soil foundation are mostly gravity drainage consolidation, such as stack preloading method, vacuum preloading method, etc. For high water content or in flow plastic mud state of the silt and clay, the efficiency of these methods are very low and cannot achieve the desired effects, the main reason is that the hydraulic conductivity of this kind of soil is very small. In the new foundation treatment methods, electroosmosis is a promising one and has been applied in many engineering in recent years, because it has the higher consolidation speed and has nothing to do with hydraulic conductivity. Electroosmosis is not a purely process of drainage consolidation, but a process of physical and chemical reactions includes the electrolysis of water, electrochemical reactions, thermal effect, the changes of pH and soil structure, ect. The traditional theories of electroosmosis ignore the influence of the electrochemical reactions, moreover, many problems such as electrode corrosion and high energy consumption, are to be better solved, all these problems restrict the development of electroosmosis, so further research for electroosmosis is essential.The major studies and achievements in this thesis are as following:1-. The paper concludes the development history, the current state of research and the actual applications of electroosmosis in geotechnical engineering; It elaborates the function mechanism and microscopic process of electroosmosis, and studies the relationship between shear strength or bearing capacity and water content at the same time; It also introduces the theory of double electrode layer and the structure models of double electrode layer of clay, in addition, it summarizes the characteristics and applicable scope of electroosmosis.2^According to the isotropy and the three-phase medium theory of soil, the paper establishes the resistance model of unsaturated clay, and calculates the resistance formula of three-phase parallel; It also researches the contact resistance between electrode and soil, and gives a concise formula of contact resistance.3、A indoor test of electroosmosis using Shenyang clay is conducted in self-made device, it studies the influence of voltage to electroosmosis and the regularity of different electrode distances to electroosmosis under the same volage gradient, through the dewatering volume, current intensity, voltage distribution, settlement, water content and bearing capacity of soil before and after electroosmosis, the results shows that electro-osmosis is effective for soft clay and the changing regularities of physical and mechanical properties of soil...