Rock Quality Designation (RQD) Calculator
This calculator is designed for geologists and engineers to determine the Rock Quality Designation (RQD), which is a measure of rock mass quality based on the length of intact core pieces over 10cm recovered during a drilling process.
Calculator
Data Source and Methodology
All calculations are strictly based on the methods outlined in the LMNO Engineering Guide. All calculations follow the established geological principles.
The Formula Explained
The formula for RQD is:
RQD = (Total Length of Core Pieces ≥ 10cm / Total Core Length) × 100
Glossary of Terms
- Total Core Length: The entire length of the core drilled.
- Core Pieces ≥ 10cm: The sum length of the core pieces that are greater than or equal to 10cm.
- RQD: Rock Quality Designation, a measure of the degree of jointing or fracture in a rock mass.
Example Calculation
Example: If you have drilled a total core length of 30m and you have 20m of core pieces ≥ 10cm, the RQD would be:
RQD = (20 / 30) × 100 = 66.67%
Frequently Asked Questions (FAQ)
What is RQD used for?
RQD is used to assess the quality of rock masses, which is critical for construction and mining projects.
Who uses the RQD calculator?
Geologists, civil engineers, and mining engineers use it to evaluate rock integrity and suitability for construction projects.
How accurate is the RQD measurement?
Accuracy depends on the precision of the core pieces measured; ensure measurements are accurate.
Can RQD be over 100?
No, RQD is a percentage and cannot exceed 100%.
Why is a piece length of 10cm used?
The 10cm threshold is a standardized measure for identifying significant fractures in geological surveys.