SPECIFICATION SHEET • SI METRIC
CAT: PROCESS

Rock Quality Designation (RQD) & RMR Index

Calculate Rock Quality Designation (RQD %) and estimated Rock Mass Rating (RMR) from drill core logs.

💡 Engineering Knowledge PrimerRock Quality Designation (RQD) measures core recovery soundness (> 10cm pieces) to evaluate rock mass quality (Bieniawski RMR system). It guides underground tunnel support design, pit slope stability, and foundation bearing capacity.
OPERATING LIMITS — RQD/RMR classification aid; select ratings from the applicable Bieniawski edition and have a geotechnical professional review it.
INPUT DESIGN PARAMETERS (SI)
m
m
MPa
points
points
points
points
CALCULATED SPECIFICATION OUTPUT
Rock Quality Designation (RQD)
✨
78 %
Estimated Rock Mass Rating (RMR)64 1
Geotechnical Rock ClassGood Rock (RMR 61-80) Text

Related planning checklists

This calculator appears in the following engineering planning checklists:

Open-Pit Mine Planning

Mining Engineer
1. Rock Quality Designation (RQD) & RMR Index2. Open-Pit Stripping Ratio Calculator3. Stockpile Volume & Tonnage Calculator

Technical Methodology & Engineering Principles

GOVERNING EQUATION
RQD % = (Sound Core Pieces > 10cm / Total Core Length) × 100% RMR = UCS rating + RQD rating + spacing rating + discontinuity-condition rating + groundwater rating + orientation adjustment
Assumptions & Scope

RMR inputs are ratings from the selected Bieniawski classification table; the tool does not infer discontinuity, groundwater or orientation ratings from core length.

Operating Range & Boundary

Use finite, physically meaningful inputs within the stated operating assumptions.