Study On Electro-Osmotic Consolidation Experiment And Theory Of Soft Soil

This paper studied the one-dimensional consolidation tests of electro-osmosis,analyzed the current, the electro-osmotic drainage, electro-osmotic coefficient,resistance, energy consumption and other parameters, summarized the variation law of each parameter, and combined the test results with the Esrig electro-osmotic consolidation theory, discussed the factors affecting the effect of electro-osmotic, and found out three factors of electro-osmotic: Effective electric potential, permeability coefficient and electro-osmotic coefficient. The traditional theories of electro-osmotic consolidation was in ideal conditions, were all assumed that the effective electric potential, the permeability coefficient and the electro-osmotic coefficient did not change in the electro-osmotic process, this did not conform with the actual,and would lead to large errors in the prediction of electro-osmosis. In order to make the nonlinear changes of the three factors considered in the electro-osmotic consolidation theory,this paper made a research on the three factors.For the electro-osmotic coefficient, because at present there was no accurate measuring method of electro-osmotic coefficient, and it could be only a rough calculation, so the variation law of electro-osmotic coefficient was very difficult to grasp. Therefore, electro-osmotic coefficient was not analyzed at the theoretical level.For the effective electric potential, designed one-dimensional experimental about the influence of electrode on electro-osmotic. In the experiment, used iron, aluminum and titanium as anode, compared the result of three electrodes, analyzed the effect mechanism of electrode on effective electric potential, and summarized the variation law of effective electric potential: the effective electric potential first decreased linearly, and then remained unchanged. Combined the traditional electro-osmosis theory with this variation law, solved the new electro-osmotic consolidation analytical when considering the effective electric potential change, and considering the influence of the load at the same time, and analyzed the solutions, respectively analyzed the effects of different loading rates and different peak load. For permeability coefficient,imported-pe log andh-ke log which were recognized at home and abroad to the traditional electro-osmosis theory, solved the analytical of one-dimensional consolidation considering the permeability change.Electrode was one of the main factors of the effective electric potential, in this paper, electro-osmotic drainage capacity of steel and aluminum were approach, andboth were stronger than the titanium electrode. For the initial contact electric potential,the steel and aluminum electrodes were close, both less than titanium electrodes.Different initial contact electric potential of different electrodes was determined by the properties of the electrode materials, and it was also related to the voltage. For the metal electrode which metallic property is medium or strong, whether high or low voltage, the electric field could overcome the binding of the outermost electrons by nucleus and formed a good current path, and the gap of the proportion of initial effective electric potential in different supply voltage was not very large. But for the weak metal electrode materials, the electric field could not completely overcome the binding of the outermost electrons by nucleus under low voltage, and only part outer electrons could be activated and had a bad current path, caused poor proportion of initial effective electric potential in supply voltage, but the electric field could activate more outer electrons with the increase of voltage and had a better current path, had a better proportion of initial effective electric potential in supply voltage.Under the voltage of 30 V, for steel and aluminum electrode, the final calculation of the electro-osmotic effect was about overrate 44% when not considering the change of the effective electric potential change compared to considering the change of the effective electric potential change; for titanium electrodes, the final calculation of the electro-osmotic effect was about overrate 50% when not considering the change of the effective electric potential change compared to considering the change of the effective electric potential change.In the case of a variable load, the average effective stress and the consolidation degree of soil increased with the increase of the loading rate in electro-osmotic when the maximum value was a certain value; the average effective stress of soil mass increased with the increase of maximum load, but the consolidation degree decreased in electro-osmotic when the loading rate was at a certain value.