METHOD FOR EXHAUSTED PIT RECLAMATION Russian patent published in 2007 - IPC E21C41/32 

FIELD: construction and mining, particularly reclamation of pit depressions after building stone and other surface mineral production.

SUBSTANCE: method involves working out pit; filling the worked-out space; leveling thereof and laying ground layer thereon. After pit working-out ditch and water-draining trenches are formed along pit perimeter to impart regular geometrical shape to pit along with pit side flattening to obtain pit sides inclination of not more than 30° along with following pit side compaction by rolling thereof with compaction machines and mechanisms; pouring sand on designed pit slopes; laying impervious screen made of high-density polyethylene on sand layer; pouring ground layer having thickness of not less than 0.5 m on the impervious screen; covering pit bottom with clay layer; compacting clay layer and inclining thereof towards collecting well composed of reinforced concrete rings; arranging radial bed drainage of crushed stone and sand on pit bottom so that the drainage is directed towards collecting well; forming water-removal ditch along pit perimeter; filling the pit with compacted building waste briquettes; arranging clay screen having thickness of not less than 0.3 m over building waste briquettes; arranging plant layer on clay screen.

EFFECT: decreased labor inputs and reclamation work costs.