Experimental investigation of flow rates through composite liners at the metric scale

Abstract

The hydraulic behaviour of 17 composite liners was investigated at the metric scale in the laboratory using 1m diameter cells. A 0.27m thick layer of clay was compacted in all cells. A GCL or a geotextile was also used at the interface in a number of cases. A 4mm diameter hole was drilled in the flat HDPE geomembrane in all experiments. In the cases GCLs were used, the influence of the pre-hydration of the GCL at the beginning of the test was studied. When comparing situations where geotextiles and GCLs were used, results tend to show that even if GCLs incorporate a geotextile the flow rates obtained with GCLs are clearly lower that flow rates obtained in the case there is a geotextile in the interface, even when the geotextile is not fully saturated.