Hydraulic Interaction between Geosynthetic Drainage Layers and Unsaturated Low Plasticity Clay

This study focuses on the impact of soil density on the hydraulic interaction between unsaturated, low plasticity clay and geosynthetic drainage layers. The hydraulic interaction was evaluated using the system hydraulic conductivity, moisture retention curves, and moisture and suction profiles obtained during transient infiltration tests. The transient infiltration tests were performed on soil-geosynthetic profiles constructed within 203-mm diameter columns. The results of the infiltration tests indicate that the soil-geosynthetic interface is affected by the capillary break effect. In particular, the results indicate that loosely compacted clays have capillary breakthrough at smaller suctions than highly compacted clays. Also, the increase in moisture storage due to the capillary break was more pronounced for looser clays.