In a tunnel project, 28 mm diameter blastholes are drilled by a drilling machine. The empty hole dia ...

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In a tunnel project, 28 mm diameter blastholes are drilled by a drilling machine. The empty hole diameter is 51 mm. The type of cut is the parallel hole cut, and the hole depth is 2 m. Assume that there is only one empty hole, and carry out the charge calculations. Also find: (a) the number of squares required for the cut; (b) burden, spacing, bottom charge height, column concentration, and stemming lengths for the other holes (wall, roof, floor, stoping); (c) column charge concentration and stemming lengths for the cut holes; (d) bottom charge heights, types of explosive, and pieces of explosive for all holes; (e) column charge heights, types of explosive, and pieces of explosive for all holes.