Influence of salinity on sedimentation during electrokinetic consolidation of dredged mud

Abstract

Electrokinetic consolidation is an innovative method for ground improvement in special conditions such as underwater construction. This method uses a weak electromagnetic field to dewater weak soils or slurries. Due to their chemical structure, water molecules act as dipoles, where the positive charge has a larger spatial distribution. Hence, when a low voltage is applied, water moves towards the cathode and can be drained there. Most current experimental studies in laboratories often use pure water, whereas weak soils located offshore or near the coastal line are often saline. It is not understood for saline soil whether a small zeta potential decreases efficacy or electromigration may reverse the negative effect. This paper presents an experimental research study on the influence of salinity on the efficacy of electrokinetic consolidation methods. The work reported herein suggests that the coefficient of consolidation increases linearly with salinity. The higher the salinity, the faster the consolidation. A salinity of 40 g/l can make the consolidation process six times faster.