GROUTING METHOD FOR WATER-BEARING HORIZON ROCK DURING VERTICAL PIT SHAFT BUILDING Russian patent published in 2005 - IPC

FIELD: mining industry, particularly to protect mine workings against underground water ingress.

SUBSTANCE: method involves drilling injection wells along pit shaft perimeter; widening cracks by supplying high-pressure water and injecting grouting mortar in the cracks; additionally boring vertical preparation well in pit shaft center. Cracks are widened by feeding water and then air or only water in vertical preparation well. Water and air are supplied under pressure lesser than pressure of hydraulic rock fracturing. Grouting mortar is injected in cracks by forcing thereof through injection wells immediately after finishing of feeding water or air in vertical preparation well. Cryogenic gel is used as the grouting mortar. Cryogenic gel is foamed before injecting thereof in wells and foamed cryogenic gel is forced into cracks beyond the pit shaft perimeter by supplying compressed air in vertical preparation well. After leaving pit shaft as it is for grouting mortar setting time wells are sunk for the next grouting step depth and above operations are repeated up to reaching the lower boundary of pit shaft interval, wherein injection is performed under pressure exceeding that on previous step.

EFFECT: reduced labor inputs and material consumption along with increased efficiency of water suppression.

3 cl, 3 dwg, 1 ex