Hydraulic Performance of GCL Seams without Field-Applied Supplemental Bentonite below a Geomembrane Wrinkle

Abstract

The hydraulic performance of geosynthetic clay liner (GCL) overlapped seams relying on hydration of panel bentonite through a melted groove in one of its geotextiles to seal the overlap is reported for the situation where the seam is below a wrinkle in an overlying geomembrane. The amount of hydrated bentonite extruded through the groove at the seam depended on whether or not the groove melt was continuous. Flow along a seam having complete groove melt with well-hydrated bentonite was 2–3 times higher than that through a single panel of GCL below a wrinkle, but two orders of magnitude lower than that through a seam with incomplete groove melt. The effect of heat tacking on the hydraulic performance of an overlapped seam is examined. The method of heat tacking, the width of the heat-tacked zone, and its positioning at the seam were found to impact seam flow.