Experimental and numerical study of electro-osmosis on kaolinite under intermittent current

Abstract

Electro-osmosis has been used as an effective technique for soft ground improvement. An axisymmetric testing apparatus was developed to study the dewatering and consolidation behaviour of kaolinite samples with different initial water content during electroosmosis under intermittent current. An axisymmetric numerical model with non-linear variation of soil parameters was developed to compare with the experiment results. With the increase of the initial water content, the electrical resistance decreased and the current through the kaolin samples increased. As a result, the total water discharge and the final surface settlement also increased. The comparison of the experiment results and numerical results validated the effectiveness of the numerical model. The change in soil parameters should be considered during electro-osmosis, otherwise the final surface settlement may be over-estimated. The formation of cracks and the friction between the soil mass and apparatus caused the deviation between experiment results and numerical results.