Experimental Study on the Electro-osmotic Treatment of Frost Boiling Damage of Cold-Region Subgrade

Abstract

In cold regions, the pore water of subgrade surface soil rises sharply because ice lenses thaw in spring-thawing seasons and cannot drain out in a short time, which leads to a high water content in the thawed layer of the cold-region subgrade. Frost boiling damage of subgrade occurs frequently under repeated traffic loads and seriously affects the normal operation of the road. Based on the advantages of rapid and effective electro-osmotic drainage, a horizontal stage electro-osmotic drainage method (HSEDM) was designed to treat the frost boiling damage of cold-region subgrade. To test the engineering effectiveness of the HSEDM, a model test was carried out, in which many key indexes, such as the current intensity, effective potential, electrode corrosion, water content, shear strength and surface settlement, were closely monitored. Through the controlled trial, it indicates that the pore water was mainly driven to move from the anode to the cathode and further drained out from the slope by electric field force. At the same time, the shear strength of the frost boiling subgrade increases significantly after electro-osmotic consolidation. The experimental results provide a theoretical basis for the engineering application of the HSEDM in the treatment of frost boiling damage of cold-region subgrade.