Embankment fill structures are often laid on formation that may develop cavities during their life-span. The use of high strength geosynthetics reinforcement to mitigate the consequences of the formation of such features provide now a solution to the problem. Designed to BS 8006-1 or EBGEO, our products can be a good cost-effective and technically sound alternative to concrete slab or pressure grouting. High strength geosynthetics reinforcement are used as tensioned membranes. Their role is to provide protection against the possibility of extreme distress occurring in the structure (in the form of major surface deformations) due to subsidence at some date after the structure has been completed. The design live over which the reinforcement is required to act will vary appreciably, depending on whether the voids will be filled as soon as they are observed, or whether no treatment is to be applied.