Practical Implications of Soil-Bentonite Slurry Wall Research

Soil-bentonite (SB) slurry trench cutoff walls have been used for over 50 years. They came into common usage in the late 1970s and early 1980s for groundwater control at excavation sites and for control of contaminant migration at contaminated sites. Yet, at the time, little research had been conducted to identify key aspects of their short- and long-term behavior. Gradually, researchers began to examine the behavior of SB walls, and in recent years, the research has increased substantially. This paper reviews research on such topics as the state of stress within the wall, consolidation and time-dependent behavior, hydraulic conductivity, and the influence of stress on hydraulic conductivity, the durability of SB under wet/dry cycles, diffusion through SB, compatibility of SB with contaminants in the environment, and osmotic behavior. The review is coupled with an assessment of the practical implications of the research.