Installation of cover lining for landfill Alt Duvenstedt
Location of work/project:
Alt Duvenstedt - Germany
HUESKER Synthetic GmbH
Installation of the GCL was simplified by the fact that the bentonite mats had been rolled onto a steel tube. This allowed straightforward placement using. The protective nonwoven installed in the area of the drainage channel ensured reliable protection of the polymer membranes.
The Alt Duvenstedt landfill site is operated by waste management company Abfallwirtschaftsgesellschaft Rendsburg- Eckernförde (AWR). It was originally capped in successive phases during the early and mid 1990s using a temporary cover system
The first step entailed the complete removal of the temporary membrane and sand bag capping system. All voids were filled with a mineral levelling material to make
the area suitable as a base for geosynthetic clay liners (GCL). After compaction by smooth drum roller, the remaining uneven edges were flattened out by hand. The first cover lining component, comprising NaBento, RL-N GCL, was placed on top of the base layer and the overlaps between the sheets sealed with bentonite powder.
The GCL was then overlaid with a vapour barrier in the form of a BAM-approved polymer membrane, as the second lining system component.
The longitudinal and transverse joints between sheets were finally welded to provide a liquidproof seal. Upon completion of the laying, jointing and testing operations, a mineral drainage layer was installed over the temporary haul roads and filled with mixed-grained re-cultivation soil, with the steeper areas being stabilised with erosion control mats.
Drainage channels were constructed at the toe of the slopes for the GCT installation by excavator with spreader bar collection and discharge of surface water. To protect the polymer membranes from the 16/32-graded filter gravel, the client specified a HaTe protective nonwoven, type B 800 “O” II, manufactured by HUESKER Synthetic GmbH.
The filter gravel layer was covered by a HaTe separating and filter nonwoven, type B 400 “O” II, and the steeper areas successively stabilised by armour stone. As is standard for landfills, the access routes on the site were designed as pervious surfacings, with a two-layer crushed stone base course and a composite PP grid, in this case Basetrac-Duo C 30 15.