Lesson 2/Learning Event 7
FIGURE 9. DRILL PATTERNS TO EXCAVATE A RAMP.
Cuts Parallel to Strike.
Dip Toward Face. When it becomes necessary to operate a face parallel to the strike with dip toward
the face, satisfactory results may be obtained by drilling inclined holes parallel to the dip and working
on the inclined face (Figure 10).
FIGURE 10. INCLINED BLASTHOLES (DIP PARALLEL TO FACE).
Dip Away From Face. This situation is more desirable than having to blast with the dip toward the face
since rock slide hazards are less severe. Vertical blastholes may be employed as for a normal full face
production blast. To eliminate overhang problems, one or more short, lightly-loaded blastholes should
be spaced between the last row of primary blastholes.