... satisfactory local support for a layer of fill located above a void that develops in the underlying foundation after the fill has been constructed by using a layer of geosynthetic reinforcement. The voids (also called sinkholes or cavities) may develop due to thawing in permafrost, collapse of mine workings...

... a 0.5 m wide cavity. Two experiments were conducted. The first one involved a geosynthetic clay liner, a nonwoven needle-punched geotextile and a high-density polyethylene geomembrane. For the second experiment, a 50 kN/m polyvinyl alcohol geogrid was imbedded within the sand layer below...