METHOD FOR RECOVERY OF EXHAUSTED OPEN PITS FOR CONSTRUCTION OF CEMETRY Russian patent published in 2017 - IPC E21C41/32 

FIELD: construction.

SUBSTANCE: method involves separate excavation, removal and storage in separate tape piles of topsoil and overburden, development of career fields, filling of exhausted space to the boundary of the upper level of ground water with construction waste, similar by composition to natural minerals with various grain size fractions, layered with followed consolidation of each layer, laying of drainage layer of building waste, with the grain size fraction 150-200 mm. Above the drainage layer an intermediate layer is backfilled with construction waste with the grain size fractions less than 120 mm. Backfilling is performed until the moment when the upper boundary of the intermediate layer reaches 1/2 of the height of exhausted space of the pit. Then, above the intermediate layer the initial backfilling of exhausted space of the pit with the mix consisting of waste rock, clay and crushed building waste with the grain fraction sizes less than 100 mm mixed in equal proportions. Moreover backfill is performed layer by layer with the thickness of each successive layer no more than 1 meter with compaction of each layer. This operation is performed before complete filling of exhausted space of the pit. Along the surface graded by bulldozer the surface of exhausted space of the pit is backfilled with the mix of sand and gravel, fraction 5, mixed in equal proportions with the minimum layer thickness 100 mm.

EFFECT: decrease of labour cost of recovery works, as well as soil protection from wind and water erosion.