Rock Quality Designation (RQD)
Term | Definition |
---|---|
Rock Quality Designation (RQD) |
A modified core recovery percentage in which only sound pieces of rock core 4 in. or more in length are counted as recovery. RQD is considered a more accurate gauge of a rock's engineering "quality" or competence than is the gross recovery percentage. It is stated as the cumulative percent of the core run occuring in pieces greater than 4 in. long.
|