METHOD OF CREATING UNDERCUT SPACE Russian patent published in 2009 - IPC E21C41/00 

FIELD: mining.

SUBSTANCE: method of creating undercut space consists in driving discharge and undercut trench workings, in breakoff of entered discharge and undercut trench workings with development raise, in drilling group of rising boreholes from entered undercut trench workings, in forming vertical opening slot, and in blasting boreholes onto formed opening slot. Undercut trench working is entered perpendicular to discharge workings. Boreholes of each group of wells at the center of formed undercut trench are drilled by one, while boreholes of each group on ends of formed undercut trench are drilled in pairs. Drilling pairs of boreholes is performed at an angle facilitating effect of blasted charges onto massif tangentially. Blasting drilled boreholes in each group is carried out simultaneously, while groups of boreholes are blasted with delay.

EFFECT: increased efficiency of discharge, increased efficiency and reduced labour intensiveness of operations.

3 dwg