Experimental Study on the Effect of Additives on Drainage Consolidation in Vacuum Preloading Combined with Electroosmosis

Vacuum-electroosmosis is a common method of foundation treatment; however, it is disadvantaged by fine soil particles clogging the drainage plate. To overcome this issue, this study treated the dredged fill from vacuum-electroosmosis with different additives. The parameters of discharged water, current, water content, and shear strength of soils treated with different amounts of Ca(OH)2, FeCl3, and NaCl were analyzed. The results showed that different additives have different effects on the vacuum-electroosmosis method for reinforcing dredger filling. Excessive additive contents were found to have an adverse effect on vacuum-electroosmosis, and hence, optimum amounts are required for the three additives. On comparing the optimum dosage of these additives, FeCl3 was observed to be the most energy-saving. From the aspect of anode corrosion and the costs involved, Ca(OH)2 was the most economical. For practical engineering applications, Ca(OH)2 was the most preferable additive. The results of this study provide guidance and scientific criteria for similar dredging foundation treatments.