Bearing capacity enhancement of skirted foundation element by electrokinetics

The objective of this study is to enhance the bearing capacity of skirted foundations embedded in marine deposits by electrokinetics (EK). The focus of improvement is at the interface between the soil and foundation. A series of laboratory tests was performed in an EK cell to determine the optimal configuration of the electrical field surrounding a skirted foundation. Two soils, namely, Yulchon clay (a natural marine sediment) and Welland sediment (a river sediment mixed with artificially prepared seawater), were tested. In each test, a steel plate was embedded in the soil to represent an element of a skirted foundation. Electrodes were installed in the vicinity of the steel plate and a voltage, either constant or intermittent, was applied over a period of time. The bearing capacity of the steel plates and the undrained shear strength of the adjacent soil were measured after electrokinetic treatment. The effect of the electrode layout and voltage application was evaluated through a comprehensive experimental program. It is evidenced that by optimising the electrode arrangement and implementing the polarity reversal the bearing capacity of the steel plates increased up to 4 times; along with the increase in the soil shear strength up to 3 times after sustained application of a DC voltage of 5.2 V for 14 days. The results obtained in this study lead to a large-scale laboratory study and will have the potential to be applied in offshore engineering practice.