Flow-rate measurements in meter-size multicomponent geosynthetic clay liners

ABSTRACT: To quantify the flow rate through multicomponent geosynthetic clay liners (GCLs), three different meter-sized specimens from different manufacturers were characterized in a dedicated experimental column. This study allows quantification of the interface transmissivity of multicomponent GCLs when the coating or attached film is damaged over an area large enough to make edge effects negligible. For all multicomponent GCLs characterized, the coating or attached film was less than 0.7 mm thick. Steady-state results indicated flow rates ranging from 4.61 × 10⁻¹² to 3.01 × 10⁻¹¹ m³/s with interface transmissivities ranging from 1.20 × 10⁻¹¹ to 7.59 × 10⁻¹¹ m²/s, which are broadly in line with flow rates obtained from conventional geomembrane (GM)–GCL composite liners. Consequently, when the coating or attached film is damaged, the thickness and rigidity of the coating or attached film appears not to affect the steady-state flow rate and interface transmissivity, which leads to a good contact at the interface.