Question

For a fair rock, the Rock Quality Designation (RQD) in percentage varies from:

• A. 0 to 25
• B. 25 to 50
• C. 50 to 75
• D. 75 to 90

Hint:

Remember: 50–75\% RQD range indicates fair rock quality.

Answer 1

The Correct Option is C

RQD (Rock Quality Designation) is a measure of rock mass quality based on the percentage of intact core pieces longer than 10 cm in a drill run. The classification is:
- 0–25%: Very Poor
- 25–50%: Poor
- 50–75%: Fair
- 75–90%: Good
- 90–100%: Excellent