Fig. 1

Fig. 1 shows the common usage of a GCL within a base seal in landfill and mining base seal applications. In this application, the flux rate of fluid leakage through the GCL is influenced by the head of fluid acting on the GCL. Typically the head should be limited to thickness of the leachate collection layer or the leachate detection layer and should be less than 50 cm. The stability of the GCL is influenced by the slope angle , the normal load gradients, and the interface friction angle , with adjacent layers. This type of single liner application is typically used for non-hazardous storage or waste material so that the diffusion rate through the GCL should be less of a concern in this type of design. Freeze/thaw effects as well as dry/wet effects are in this application only a design issue during the initial phase and are typically not an issue once the total thickness of cover material over the GCL is greater than 1m (3 feet).

Bentofix® GCLs with one woven and nonwoven component are best suited for this application if the cover material is sandy. In other cases more robust geotextile components may be suitable such as double sided nonwovens. Bentofix® GCLs with a nonwoven on both sides typically allows steeper designs than with woven components, due to an increase of the interface friction angle.