Investigation on the properties of compacted silty clay subjected to electro-osmosis using bender element

Abstract

The moisture content of subgrade soil in seasonally frozen regions is often higher than its optimum value, leading to a decline in mechanical properties and a reduction in subgrade bearing capacity. Electro-osmosis has shown promise as a technology for controlling subgrade moisture, but significant heterogeneity has also been observed in treated soil. This study investigates the impact of electro-osmosis on soil stiffness through a series of bender element tests of compacted clay. The effects of dry density and supply voltage on the performance of electro-osmosis treatment and the layered structure and anisotropy of the soil were analyzed. The results show that electro-osmosis treatment increased the shear wave velocity of the soil by 140% compared to untreated saturated soil and by 70% compared to soil with optimum water content. It has also been found that layered compaction of soil resulted in a layered structure, with electro-osmosis having a more prominent impact on soil near the cathode, resulting in a more pronounced layered structure. Besides, electro-osmosis was found to enhance soil anisotropy, particularly near the anode. Increasing the dry density and voltage levels can help improve soil uniformity. These findings provide insights into the potential use of electro-osmosis in improving soil stiffness, which could benefit various engineering applications.