The present study focuses on the performance of various impervious barriers of cover systems subjected to differential settlements. Various impervious barriers, namely Compacted Clay Liner (CCL), Geosynthetic Clay Liner (GCL) and Fibre Reinforced Clay Liner (FRCL) were subjected to differential settlements artificially in a centrifuge using hydraulic trap-door system. Distinct delay in water breakthrough was observed for a clay liner reinforced with discrete and randomly distributed fibres when compared to an un-reinforced clay liner. Limiting maximum distortion level of 0.068 was registered for a 0.6 m thick clay liner. In comparison, this was observed to occur at 0.078 for a FRCL of identical thickness. Even after inducing distortion level of 0.125, GCL has not shown any distress. For the type of impervious barriers tested, the ability of GCLs to withstand differential settlement was found to be superior to that of CCLs.
Keywords: landfills, municipal solid waste, clay liners, GCL, geosynthetic clay liner, fibre reinforcement, centrifuge modelling, differential settlements, cracking, hydraulic conductivity, performance evaluation, deformation, landfill barriers, waste management