METHOD FOR RIVER ICE BLANKET BREAKAGE Russian patent published in 2007 - IPC E02B15/02 F42D7/00 

FIELD: cleaning or keeping clear the surface of open water, particularly blasting works to prevent ice jams.

SUBSTANCE: method involves supplying explosion gaseous mix in gas-tight shell arranged under ice blanket by alternate air and combustible gas injection; initiating gaseous mix explosion. Holes are preliminarily drilled in ice blanket in direction transversal to river bed so that the holes are equally spaced one from another. Stream velocity is measured in each hole to determine kinetic energy of river stream. Then kinetic energy distribution along hole sections is plotted and area corresponding to selected ice blanket breakage zone width is determined in area characterized by maximal kinetic energy density. After that necessary number of holes to be made in zone of gas-tight shells arrangement is specified from ice blanket thickness and gas-air mixture amount enough for explosion for selected ice blanket breakage zone width. The shells are made as sleeves and provided with parachutes and floats with weights. Cuts are formed in ice blanket breakage zone so that the cuts extend for depth equal to half of ice blanket thickness in longitudinal and transversal directions with respect to river bed.

EFFECT: improved ice pieces removal from ice breakage zone due to optimal gas-tight shell location under ice blanket and simplified gas-tight shell installation.

4 cl, 1 ex