Interface shear strength and the soil softening effect on the soil-geocomposite drainage layer system stability

Geosynthetics are commonly used to support solid waste landfill facilities as a liner system due to their low permeability. The application of Geocomposite drain (GD) are increasingly in civil engineering specifically on geotechnical and geocnvironmcntal system. GD consist of a high flow capacity drainage core with a non-woven gcotextiles filters/separator cover. In landfill capping system, GD has been used as a drainage layer. The soil-geosynthetics or geosynthetic interfaces play a major role in the landfill cover system's performance. This research work discussed the finding on the field work measurement of the landfill cover system. The trial site of landfill was carried out to investigate the effect of soil water content on the soil-GD interface shear strength of landfill cover/capping. The performance of landfill cover soil panel using different types of geosynthetic drains was studied. The finding suggests that the softening soil layer at the interface of soil-geosynthetic drainage reduces the shear strength as a results of the water accumulated behavior, and this issues has to be addressed in design specifications and construction control for landfill cover system.