Theoretic And Experimental Analysis Of Electro-osmotic Character And Efficiency For Soft Clay

Deep deposit soft clay exists extensively in waterfront area of China. Its properties include small size of its compositive particle, high water content and low bearing capacity. Usual foundation treating methods such as preloading method, vacuum preloading method could not achieve a satisfactory result or even could not be applied. Electro-osmosis can achieve a satisfactory result in this situation because electro-osmotic permeability is several times or even a hundred or more than hydraulic permeability. However, the application of electro-osmosis was limited by its great energy demand. Therefore, it was necessary to make further theoretic and experimental research on electro-osmotic character and efficiency.After summarizing and analyzing the application of electro-osmosis in geotechnical engineering, series of tests were conducted on electro-osmotic consolidation by using nansha silt, which aim at studying on associated theory and application technology. The major studies in this thesis are as following:Firstly, series of electro-osmotic model test were conducted by using the Guangzhou Nansha District silt soil samples to make research on variation of each electro-osmotic parameters of electro-osmosis process under different electric field intensity. The characters of electro-osmotic parameters such as cumulative effluent volume and current intensity varied with time were acquired.Then the electro-osmotic model theory was studied. The formula of electro-osmotic coefficient of permeability circular hole based on the assumption of Helmholtz-Smoluchowski model was given, which can improve the calculation of electro-osmotic coefficient of soil.Finally, series of electro-osmotic tests were conducted based on the soil has different activity to test and analyze the electro-osmotic efficiency and applicability of different types of soil and finite element analysis was conducted to analyze the distribution of electric field in the soil of electro-osmotic model, which can provide reference data for design of electro-osmotic consolidation.In summary, this paper has done a lot of theoretical and experimental work about electroosmosis in order to benefit the engineering practice.