Studies must be carried out to guarantee the drainage of any water that, by running between the membrane and soil mass, can reduce to zero the soil/membranes’ coefficient of friction. If such a situation developed, the soil mass overlying the impermeable membrane would be subject to slippage.
The soil spread onto the landfill slopes is subject to forces that tend to cause slippage towards the base, and to other forces that favor stability. If these forces are not equalized with an acceptable safety factor, then it is necessary to use a suitable geosynthetic material capable of conferring to the topsoil those properties required for guaranteeing stability.
TENAX MULTIMAT R reinforced geomats or TENAX TENWEB geocells, by means of their high frictional three-dimensional structure, allow for the retention of a thick layer of topsoil even on steep slopes.
Placed directly above the impermeable membrane (or if required, above a filtering-draining TENAX TNT geocomposite), they are secured in place either in an anchor trench at the crest of the slope or secured to a permanent structure using suitable fixing pins. Once installed, topsoil can be placed, compacted and if required seeded.