METHOD OF FORMATION OF EXTENSIVE SOIL OPENINGS BY EXCAVATING BLAST Russian patent published in 1997 - IPC

FIELD: formation of extensive soil openings. SUBSTANCE: drilling of rows of vertical deep-holes, placement of explosive charges in them, installation of live primers, stemming of deep-hole upper part, laying of blasting network and subsequent blasting. Length of deep-hole charges is determined by formula: L=1,1HC, m. Distance between deep-holes is determined by formula: , where H - design depth of opening, m; d - deep-hole diameter, m; γ - charge linear density (mass), kg/m; K - estimated specific consumption from charge center to open surface, m; C = 0,5+γ•C_expl./C_dr. - dimensionless coefficient, depending on cost of drilling of 1 m of holes, C_expl. (rouble/m) and of 1 kg of explosive in hole, C_dr. (rouble/kg). EFFECT: enhanced efficiency. 5 dwg