Introduction. Various techniques of breaking rock by explosion have currently been developed when tunneling underground mine workings, but asymmetrically directed stress fields application is of the main interest. Research aim is to study explosion energy distribution and maximum concentration deep down the blasted rock mass. Blast energy concentration may be achieved by using the principle of cumulation in the hole back by means of changing the design of the blasthole explosive charge. Methodology. Based on the analyzed literature and theoretical research it is recommended to use the design of a blasthole explosive charge with the use of Munroe effect, which makes it possible to increase the blasthole efficiency ratio (BER), reduce drilling activity, reach sharper design contours of mine workings and eliminate bootlegs. The action of blasthole explosive charges with Munroe effect has been theoretically investigated, hydrodynamic theory of cumulation has been studied, and the dependences have been determined between the liner’s collapsing angle alternation and the radius of the cone, its height, initial velocity, and cumulative jet velocity. Results. The main factors which determine the efficiency of the proposed new technique of blasting against the basic technique are the blasthole efficiency ratio, face advance pace after one blast, the amount of rock mass detached after one blast, and the granulometric composition of the blasted rock mass. Summary. The developed design of the blasthole explosive charge with Munroe effect makes it possible to increase BER, face advance per one cycle, and increase the amount of the broken rock mass.
3D representation of geological observations in underground mine workings of the Upper Silesian Coal Basin
