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The growing use of self-propelled equipment in mines has made it necessary to enlarge tunnel cross-sections substantially (by a factor of 1.5-2). Combined with the movement towards mining at ever greater depths and in more complex geomechanical situations, these developments make particularly important the proper wall shaping of mines.Although some positive experience has been gained in the USSR and other countries with this method under various mining conditions, the extent of wall-shaping blasts, especially in nonferrous metal mines, remains limited to 10-15%. The main obstacle to a wider practical application of this method (in addition to secondary factors such as the design of specialized tunneling machines, devices for exact blast-hole marking, etc.) is the lack of adequate cost-benefit analyses and evaluations of all the factors that determine the efficiency of this method of mine-wall shaping.

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