Prevention of rock and gas outbursts in super deep-level mining in Internatsionalny Mine

Abstract

The method of advanced perimeter blasting has found effective application in development heading and stone drivage. The method uses various drilling-and-blasting scenarios subject to the alteration ingeological and geotechnical conditions, and with regard to the spatial location of outburst-hazardous strata relative to the section of a mine road being driven. This article describes the actually implemented prevention of gas-dynamic events using the method of advanced perimeter blasting, and the case-study of the method applied in the outburst-hazardous carbonate rock mass in super deep-level mining in Internatsionalny Mine (depth of 1200 m and more). The records of the gas-dynamic events in the course of drivage with anti-outburst measures are analyzed. The semi-commercial tests of advanced perimeter blasting are described with patterns of drilling and blasting, and designs of charges in shooting outburst-hazardous beds. The effect of blasting on fracturing is estimated by calculation of the blast impact zones as function of the charge mass and length. The observations over variation in the geomechanical and geodynamic behavior of rock mass during drivage with the perimeter blasting efficiency control are analyzed. The studies included examination of geodynamic characteristics of dolomite rock mass susceptible to rock and gas outbursts and the performance evaluation of the preventive advanced perimeter blasting. The quantitative figures on gas-dynamic phenomena and events in striking and intersecting outbursthazardous dolomite beds are given in graphical form. The flow chart of the semi-commercial testing of advanced perimeter blasting is presented, and the fracturing zones induced by the explosion-generated shock in advanced perimeter blasting are calculated.