ABSTRACT
Strength of Is (50), MPa >10 4-10 2-4 1-2 For this low range UCS preferred intact rock UCS, MPa >250 100-250 50-100 25-50 5-25 1-5 <1
Rating 15 12 7 4 2 1 0
Drill Core Quality RQD, % 90-100 75-90 50-75 25-50 <25 Rating 20 17 13 8 3
• The discontinuity rating shows it to be the most important parameter in evaluating the rock rating.
