Since the introduction of geosynthetic clay liners (GCLs) to waste containment facilities, one of the major concerns about their use has been the hydraulic equivalency to a compacted clay liner as required by regulations. Laboratory test results and more recently field observations show that the thickness, or mass per unit area, of hydrated bentonite in a GCL can decrease under normal stress, especially around zones of stress concentration or nonuniform stresses, such as a rock or roughness in the subgrade, a leachate sump, or wrinkles in an overlying geomembrane. This paper describes the effect of bentonite migration on the hydraulic equivalence between a GCL and GCL and the contaminant transport through a thinned GCL. Finally, the paper presents suggestions for protecting hydrated bentonite from stress concentrations and reducing contaminant transport through a GCL.
ASJC Scopus subject areas
- Civil and Structural Engineering
- Building and Construction
- Geotechnical Engineering and Engineering Geology