Hydraulic Conductivity of Partially Prehydrated GCLs under High Effective Confining Stresses for Three Real Leachates

Reinforced GCL samples from three different projects were partially pre-hydrated on native damp subgrade soils for several weeks, and were then tested for hydraulic conductivity using three real leachates under a variety of effective confining stresses. The samples permeated with MSW leachate were tested under effective stresses of 240, 480, and 720 kPa. The samples permeated with MSW-incinerator ash leachate were tested under effective stresses of 180, 360, and 530 kPa. The samples permeated with pulp & paper waste leachate were tested under effective stresses of 165, 340, and 475 kPa. All of the results showed decreasing hydraulic conductivity with increasing effective stress with the ash leachate being the most sensitive to effective stress, and the pulp & paper leachate being the least sensitive. The hydraulic conductivity of the GCL samples to all of the leachates tended to level off to a common value of about 2 x 10^–12 m/s at effective stresses above 475 kPa.