Numerical modelling of dredged sediment improvement under electrokinetic geosynthetics assisted vacuum preloading combined with electroosmosis

The absence of multi-physics modelling frameworks limits the optimisation of electrokinetic geosynthetics (EKG) assisted vacuum preloading combined with electroosmosis (VPE) technique for the consolidation and remediation of dredged sediments. A multi-physics coupling model was therefore developed that integrates electrical, hydraulic, mechanical, and chemical fields to simulate the consolidation and remediation processes in VPE. EKG assisted VPE experiments were conducted to verify this model. Results for electric field intensity, excess pore water pressure, settlement and Cu concentrations showed that the model accurately captured both consolidation and remediation behaviour in VPE treatment. Numerical results further revealed that electrical conductivity variations led to uneven distribution of electric potential. Electric potential was concentrated near the anode over time, subsequently influencing electroosmotic flow and electromigration. The dissipation of excess pore water pressure within the dredged sediments was promoted by VPE through the formation of negative pressure. At the anode, the dissipation of excess pore water pressure and the transport of Cu were primarily controlled by electrical conductivity variations, whereas at the cathode, excess pore water pressure dissipation and Cu accumulation were predominantly influenced by clogging. • EKG-assisted vacuum preloading-electroosmosis improves dredged sediment properties. • This model can capture consolidation and remediation process of dredged sediment. • Electrical conductivity dominates negative pore pressure dissipation in the anode. • Clogging dominates negative pore pressure dissipation in the cathode. • Anode Cu migration is significantly affected by electrical conductivity.