RU2000102245A - METHOD OF DESTRUCTION OF WHOLE - Google Patents

Claims (1)

A method for destroying pillars, including drilling in a series of wells parallel to two outcrop surfaces and oriented from one pillar flank adjacent to a rock mass to another, staggering wells, placing explosive charges in the wells, and sequential destruction of the pillar mass by simultaneous blasting explosive charges in opposite rows on two parallel pillar exposure surfaces with the formation of attenuating cavities with a displacement relative to each other by half the distance between them final destruction of the pillar central portion blasting explosive charge, characterized in that the weakening cavities are formed to the depth
L = W (n-1);
where n is the number of rows of borehole explosive charges;
W - bhp explosive charges of a number, m;
L is the depth of the attenuating cavities, m;
the central part of the pillar is formed in a sinusoidal shape with an amplitude equal to half the width of the pillar and a half-period equal in terms of the distance between the symmetry axes of the opposite attenuating cavities, and the part of the pillar of the sinusoidal form is blasted off from its segments from the rock mass by blasting explosive charges on the flanks, and explosive charges located opposite the vertices of the sinusoidal part of the pillar and explosive charges located through one of them explode ahead of other charges of the explosive sinusoidal part of the target ka.