METHOD OF RELIEF OF WORKING MARGINAL ROCK MASS AND SHAPED CHARGE FOR FORMATION OF INITIAL FISSURES Russian patent published in 1997 - IPC

FIELD: mining industry; applicable in mining of stratified coal deposits for relief of hazardous concentration of stresses in seams prone to outbursts of coal and gas. SUBSTANCE: the invention offerers a method of directed hydraulic fracturing and parameters of depth of relieving holes, length and location of initial fissure, required length of hole interval between holes depending on the texture and structure of rocks of main roof. Initial fissure is made by blasting of special shaped charge oriented along the working. Shaped charge consists of a body with longitudinal slot for charge hollow of explosive charge located inside the body. Damping stemming is located between upper and lower covers of the body and separating covers, and also between charges and body walls. After blasting of shaped charge, liquid is injected in the mode of hydraulic fracturing and development of the surface of breakage within the preset limits takes place. EFFECT: higher efficiency of relief of working and removal of stress hazardous concentration. 6 cl, 6 dwg