METHOD FOR DRILLING OF BLASTING OPERATIONS Russian patent published in 2006 - IPC F42D3/00 F42D5/00 

FIELD: hydraulic engineering at dredging operations, construction of profiled depressions and other special blastings, when blastings are to be conducted under water according to specifications.

SUBSTANCE: the method consists in drilling of a net of boreholes from a surface platform, placing of the main charges in them, placing of an additional charge in the entrance of each borehole removed from the main charge by a space filled by an inert medium, production of the explosion line with the use of a non-electric system of ignition, simultaneous blasting of the additional charges and initiation of the main charges after time interval the amount of additional charge G is determined from relation: kg; where a₁ - the distance between the adjacent boreholes, m; - water density, kg/cu.m; H - height of the water column above the borehole entrance, m; P_a - atmospheric pressure in the zone of blast, kg/cu.m; K₁ - coefficient equal to 4,12 kg/cu.m; and time interval is determined from relation: where P_rv.=P/P_a - reduced value of hydrostatic pressure of water on the additional charge; P - value of hydrostatic pressure of water on the additional charge, kg/sq.m; K₂ - coefficient equal to

EFFECT: enhanced efficiency of drilling and blasting operations, intensity of crushing and ejection of broken rock mass at a reduced harmful effect of the blast on the environment.

8 cl, 2 dwg