DEVELOPING ENTRY MAINTENANCE METHOD Russian patent published in 2006 - IPC E21D11/00 

FIELD: mining industry, particularly to excavate single and series of superimposed flat-lying and inclined seams during chamber-and-pillar mining.

SUBSTANCE: method involves forming artificially weakened layer having predetermined strain characteristics by drilling equally-spaced horizontal well row, wherein the wells of the row are drilled from developing entries so that the wells are transversal to developing entry axes and extend in opposite directions in advance of secondary work line. The wells are drilled at height h from developing entry ground. The h is determined as h=(5/6)·m, where m is seam thickness, m. Well length L is equal to L=6B, where B is developing entry width. Distance K between adjacent well centers in horizontal direction K=16d, where d is well diameter, m. Well drilling advance degree M is determined from M=2l₂, where l₂ is unbalanced bearing pressure zone length, m.

EFFECT: increased stability of developing entries, reduced costs of developing entry maintenance and increased safety of mine operation performing.

3 dwg