Electrocementation of a Marine Clay Induced by Electrokinetics

摘要

This study is directed to using electrokinetic processes for strengthening marine sediments in order to enhance the performance of skirted foundations. This paper studies the electrocementation that occurs during the electrokinetic treatment of a highly saline marine clay. 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 was significantly lower, and the pore diameters were significantly smaller than in of the untreated soil samples. The plasticity characteristics of treated soil were also changed after electrokinetic treatment; this is attributable to the electrokinetically enhanced grouping of clay particles into aggregates due to the presence of cementing agents and changes in type and concentration of ions in the soil pore water. The amounts of iron oxide and calcium carbonate, both well-known cementing agents in soil, increased after electrokinetic treatment; this increase contributes to the increase in soil shear strength and decrease in soil pore size. The results of CEC and glycol retention tests indicated that the surface charge of clay particles at the anode sides was reduced after electrokinetic treatment, leading to stronger interparticle bonds.