METHOD OF EXECUTION OF BLASTING OPERATIONS Russian patent published in 1998 - IPC

FIELD: drilling and blasting operations in hard rocks in various branches of industry where blasting operations are conducted in rock masses. SUBSTANCE: method of execution of blasting operations includes preliminary loosening of rock mass by drilling of additional blast holes, by their charging with explosives and short-delay blasting with definite delay. Novelty of proposed method lies in division of rock mass into separate blast blocks, in drilling and blasting first odd and then even blocks. In this case groups of hole charges of odd blocks are exploded in lateral rows starting from middle of each block at moment of passage of amplitude of wave of stresses from blast of previous group of charges. This amplifies amplitude of pulse of stresses along its travel and forms simultaneously flat front of wave of stresses in backward direction which causes alternating loads on mass of even blocks. EFFECT: reduced expenses for drilling and blasting operations thanks to preliminary loosening of strength properties of rock mass by means of directed multiple alternating blast action. 1 cl, 1 dwg