ABSTRACT
Geosynthetics may be used in surface capping for various purposes: to improve gas removal, reduce infiltration of rain into the landfill, and improve the stability of capping constructions. In Northeim county at the Blankenhagen Landfill Site, each section of the tip for municipal waste that has reached the final height is covered. Whether the waste is capped by an impermeable geomembrane or by a mineral seal of low permeability, excess rainwater seeping through the soil cover has to be removed. The drainage capacity of geosynthetic composites consisting of a three-dimensional, coarse, open drain core with one or two nonwovens is very satisfactory. The functioning of the non-woven covering the drain core will be farther discussed here. Friction tests indicate that if mineral layers are chosen for impermeabilization the stability of the construction is only slightly reduced by the incorporation of a geosynthetic drain.
