Experimental Study On The Influencing Factors Of The Contact Resistance On Electro-osmotic Consolidation

Beach area has been one of the hot spots of geotechnical engineering with the development of coastal cities.Because of high clay content,poor permeability,high water content of tidal mud,traditional drainage consolidation technology cannot work effectively,such as vacuum preloading etc.The electroosmosis technique has attracted more and more attentions because of the advantage that the coefficient of electroosmosis has nothing to do with the soil particle size.However,the electro-osmotic treatment technology still has the problems of low electro-osmotic efficiency and high electro-osmosis energy consumption.And the research on the contact resistance problem is not enough which is an important factor affecting the effective potential and electro-osmotic efficiency.There is practical significance to widen the field of application of electroosmosis in practical engineering by exploring the ways to reduce the contact resistance and improve the efficiency of electroosmosis.In order to study the influencing factors for contact resistance during electroosmotic consolidation,a series of electroosmosis model tests were conducted with aluminum electrodes and beach silt on the condition of same potential,such as anodes with different degree of corrosion and different conductive areas.The effect of different soils on the electroosmotic effect were studied by using the infiltrating mud,the muddy mud and the soft soil of Ningbo.The displacement,current,potential and moisture content after the test were measured.The following conclusions are obtained:When the electrode is an aluminum electrode,the electrode corrosion has little effect on the electroosmotic effect during the whole electroosmosis process.Improving the conductive area can reduce the contact resistance,improve the current,speed up drainage,thereby improving the efficiency of electroosmosis and shortening the duration.The ratio of the anode conductive area and the cross-sectional area of the soil sample has an optimal value.While the value is higher than the optimum value,there will be waste of energy consumption.The optimal value can be determined by the electro-osmotic test.The treatment of silt is the best,and it is suitable for electro-osmotic treatment.The treatment period of tidal mud is shortest and the development of fractures is fast,and it needs to be used in combination with other processes.The energy consumption coefficient of Ningbo soft clay is the lowest,but the treatment period is long,Moisture content distribution of Ningbo soft clay is relatively uniform.