METHOD OF SOFTENING OF SURFACE LAYER OF OPENCAST BENCHES IN SEASONAL GROUND FREEZING Russian patent published in 2002 - IPC

FIELD: mining industry; applicable in stripping operations in opencasts in winter period of year on soft ground of seasonal freezing. SUBSTANCE: drilling of holes by drilling machines in frozen surface layer of ground from side of slope, parallel to slope surface is performed through entire depth of slope by rows whose axes are perpendicular to slope plane with minimum space between holes according to drilling conditions, and distance between rows is less that bucket width of opencast excavator executing stripping of overburden rocks. Holes are also drilled in bench foot, in one row through depth of ground freezing with minimal distance between holes. Softening of frozen surface layer of working platform of bench is performed by trench rotary bucket excavator by excavating trenches parallel to one another along bench through depth of ground freezing with formation of connectors between them and back filling of trenches by excavator belt conveyor. EFFECT: higher efficiency of stripping operations in winter time due to reduced expenditures for softening of frozen surface of bench ground. 3 cl, 2 dwg, 1 ex