Electro-Cementation of a Marine Clay Induced by Electrokinetics

摘要

This study is directed to using electrokinetic processes for strengthening of marine sediments in order to enhance the performance of skirted foundations. In this paper, electro-cementation that occurs during the electrokinetic treatment of a highly saline marine clay is studied. The influence of electrokinetics on the soil structure is characterized by changes in the pore size distributions determined by mercury intrusion porosimetry. The porosity of the treated soil samples is significantly lower and the pore diameters were significantly smaller than those of the untreated soil samples. The plasticity characteristics of treated soil are also changed after electrokinetic treatment attributed to the electrokinetically enhanced grouping of clay particles into aggregates at presence of cementing agents and changes in type and concentration of ions in the soil pore water. The contents of iron oxide and calcium carbonate, both are well-known cementing agents in soil, increased after electrokinetic treatment, which contribute to the increase in the soil shear strength and decrease in soil pores size. The results of CEC and glycol retention tests indicate that the surface charge of clay particles at the anode sides was reduced after electrokinetic treatment, leading to stronger interparticle bonds.