Long-term field test of a clay geosynthetic barrier in a landfill cover system

摘要

A test field of 520 m~2 was installed on the cover of a municipal solid waste landfill in Bavaria in order to test a landfill capping system using a geosynthetic clay liner (GCL) as barrier layer. The test field was constructed as a large-scale lysimeter, in which the relevant water fluxes are collected and measured at high resolution and precision. The water balance of the 3-years monitoring period up to now shows, that evaporation accounts for almost 70% of the water output. 30% drain off laterally in the drainage geocomposite and only 0.5% seep through the GCL. In-situ-measurements of moisture within the bentonite of the GCL show seasonal changes in water content. Obviously the 1 m thick recultivation layer does not completely shield the GCL from desiccation stresses. Over all the GCL proved to be an effective sealing layer within the landfill cover system during the 3-years observation period.