METHOD OF CUT-HOLE FORMATION Russian patent published in 2009 - IPC F42D3/04 E21D9/00 

FIELD: explosion operations.

SUBSTANCE: invention can be applied in mining, railway construction, drilling and blasting driving of horizontal and sloping mines and railway tunnels. Method of cut-hole formation involves drilling of perimetre well and cut-holes around it, with distance between cut-holes and well depending on acoustic impedance rate of rock, charge diametre in blasting hole, charging density, explosive performance and rock density; and detonation of blasting holes. Minimum distance between generatrices of cut-hole and well is defined by expression accounting for fissility, physical properties of rock, detonation properties of explosives, overburden pressure and perimetre well diametre.

EFFECT: possible determination of distance between cut-holes and perimetre well depending on the listed parametres of drilling and blasting and physical and operational properties of rock, formation of high-quality cut-hole and given ratio of advance per blast hole during pit and tunnel driving, enhanced safety level of driving works.

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