ABSTRACT
Especially in landfill lining systems and mining, the compressive loads on the sealing system and the overlying drainage system are enormous. They must be absorbed by the geosynthetic drainage systems without damage and without compromising hydraulic performance, i.e. sufficient water flow capacity.
Newly developed, integrally manufactured geosynthetic drainage sheets (GDS) made of high-density polyethylene (HDPE), which are based on a new, patented process, are being tested in laboratory trials on specimens produced in the laboratory. In particular their short-term compressive behavior and their water flow capacity under high compressive stresses with soft bedding were investigated. The results of the novel GDS are also compared with laboratory-made geonet structures. While geocomposites with geonet drainage cores suffer very severe losses in water flow capacity under the influence of surcharge and even more so under the influence of soft bedding, drainage geocomposites made of the novel GDS show a much smaller decrease and better performance than conventional products.
Weaknesses of biplanar geonets with regard to compressive behavior under the influence of compressive loads as well as a reduction of hydraulic effectiveness with ribs running obliquely to the slope are specifically circumvented by appropriate selection and size of the waterway grooves of the GDS running in the machine and cross-machine direction.
