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ON METHODS OF FORMING OF FISSURE STRESS CONCENTRATOR AT BORDER ZONE OF HOLE

The analysis of methods and equipment for forming of fissure stress concentrators in the walls of holes for practical realization of method of directed measuring hydraulic fracturing is represented. Having based on carried out review the classification of known equipment by method of forming of initiating fissure such as mechanical cutting of fissure by spinning instrument, denting of hard-alloy indentors to hole walls, impact using plastic substance, explosion of cumulative charges is proposed. It is established that mechanical method is the most widespread by numbers of patented technical solutions and by rate of practical realization. Known equipment provides forming of fissure stress concentrators only in soft rocks and rocks of medium hardness. It is concluded that it is necessary to study and develop new methods and equipment for forming initiating fissures providing of realization of directed measuring hydraulic fracturing into ore solids.