Datarock Knowledge Base

Product descriptions

Rock Quality Designation (RQD)

This document details Datarock’s product Rock Quality Designation (RQD) that uses two key methods as documented in the original literature.

We assess the core and sum the pieces that are greater than:

10cm; and
Two times the core diameter.

Literature

This product is based on the following literature:

Title	Author	Year
Technical Description of Rock Cores for Engineering Purposes	D. Deere	1963

Dependent Models

The outputs of the following models are used to determine RQD:

Model Name	Model Type
Coherent Rock	Instance Segmentation
Drillers Break	Object Detection

Data Processing

The outputs of the Coherent Rock and Drillers Break models are combined to create an understanding of natural coherent rock pieces.

Coherent Rock

The Coherent Rock model identifies all pieces of cylindrical pieces of drill core, and draws a polygon around each piece. Following the depth registration process, the length of each piece of coherent rock is known, allowing for categorisation and measurement of all coherent rock to determine the proportion of rock pieces greater than 10cm in length.

Mechanical Breaks

The Drillers Break model identifies unique, hand drawn break marks on the core. These are typically red crosses, however can be any unique mark.

Breaks in coherent rock are determined mechanical, if:

The gap between the two pieces of coherent rock is less less than 50mm wide; and
Drillers break marks appear on both sides of the break, and be not further than 70% of the length of the rock away from the break.

RQD Analysis

The following images show example categorisation, including polygons greater than 10cm are shown in purple and less than 10cm magenta.

rqd-1

rqd-3

rqd-2

rqd-4

RQD is then calculated based on the equation below.

rqd-5

Product Configuration Options

Configuration	Options
Treatment of core loss	Core loss can be treated as either: Incoherent Rock (default); or Missing Data

Configuration

Options

Treatment of core loss

Core loss can be treated as either:

Incoherent Rock (default); or
Missing Data

Output Intervals

Default interval length: 1.0m

Customisable interval available: Yes, via uploading sample table to platform (see User Data below)

User Data

Sampling Intervals

User data may be uploaded to the platform via csv in the following format:

HOLEID_sample.csv

CSV file to contain the following headers:

File Header	Description
depth_from	Start of interval
depth_to	End of interval
rqd_m	Site measured length of coherent rock pieces longer than 100mm
rqd	Sum of site measured length of coherent rock pieces longer than 100mm divided by interval length, multiplied by 100

Core Diameter

To calculate RQD based on core diameter, the data should be uploaded via csv in the following format:

HOLEID_core_diameter.csv

CSV file to contain the following headers:

File Header	Description
depth_from	Start of interval
depth_to	End of interval
core_diameter	The core diameter / drill bit size such as NQ, HQ, PQ etc

Data Output

Results from this class of models can be obtained using the Download artefacts option from the Actions button in the Model Review tab of Datarock. The available CSV files include the following:

ProjectName_rqd_by_metre_intervals.csv
- This file contains the below data on even metre increments
- File headers are outlined in this table:

File Header	Description
hole_id	Customer’s Hole ID
depth_from_m	Start of interval (metres)
depth_to_m	End of interval (metres)
depth_from_ft*	Start of interval (feet)
depth_to_ft*	End of interval (feet)
rqdm_10	Sum of Datarock measured length (in metres) of coherent rock pieces longer than 100mm
rqdft_10*	Sum of Datarock measured length (in feet) of coherent rock pieces longer than 100mm
rqd_10	Sum of Datarock measured length of coherent rock pieces longer than 100mm divided by interval length, multiplied by 100
rqdm_2xdia	Sum of Datarock measured length (in metres) of coherent rock pieces longer than two times the provided core diameter. This will only be provided if core diameter data has been uploaded to the Platform.
rqdft_2xdia	Sum of Datarock measured length (in feet) of coherent rock pieces longer than two times the provided core diameter. This will only be provided if core diameter data has been uploaded to the Platform.
rqd_2xdia	Sum of Datarock measured length of coherent rock pieces longer than two times the diameter of the core divided by interval length, multiplied by 100. This will only be provided if core diameter data has been uploaded to the Platform.
core_diameter	The core diameter / drill bit for the given interval (e.g. NQ, HQ, PQ) that the coherent rock has been assessed against. If there are no coherent rock pieces in the interval, this will be blank. This will only be provided if core diameter data has been uploaded to the Platform.
core_diameter_mm	The core diameter in millimetres associated with the drill bit. If there are no coherent rock pieces in the interval, this will be blank. This will only be provided if core diameter data has been uploaded to the Platform.
driller_breaks_count	Number of drillers breaks (mechanical breaks) detected
coherent_rock_length	Length of coherent/whole core in metres
incoherent_rock_length	Length of incoherent/broken rock in metres
coreloss_length	Total recorded core loss in metres
non_rock_length	Combined length of empty tray and core block in metres
timestamp	Time of model prediction
version	A model version identifier

*Only included if project depths are in feet.

ProjectName_rqd_by_user_intervals.csv
- This file is generated on holes where user data is uploaded to the platform.
- It contains the below data based on the user data.
- File headers are outlined in this table:

File Header	Description
hole_id	Customer’s Hole ID
depth_from_m	Start of interval (metres)
depth_to_m	End of interval (metres)
depth_from_ft*	Start of interval (feet)
depth_to_ft*	End of interval (feet)
rqdm_10	Sum of Datarock measured length (in metres) of coherent rock pieces longer than 100mm
rqdft_10*	Sum of Datarock measured length (in feet) of coherent rock pieces longer than 100mm
rqd_10	Sum of Datarock measured length of coherent rock pieces longer than 100mm divided by interval length, multiplied by 100
rqdm_2xdia	Sum of Datarock measured length (in metres) of coherent rock pieces longer than two times the provided core diameter. This will only be provided if core diameter data has been uploaded to the Platform.
rqdft_2xdia	Sum of Datarock measured length (in feet) of coherent rock pieces longer than two times the provided core diameter, multiplied by 100. This will only be provided if core diameter data has been uploaded to the Platform.
rqd_2xdia	Sum of Datarock measured length of coherent rock pieces longer than two times the diameter of the core divided by interval length. This will only be provided if core diameter data has been uploaded to the Platform.
core_diameter	The core diameter / drill bit for the given interval (e.g. NQ, HQ, PQ) that the coherent rock has been assessed against. If there are no coherent rock pieces in the interval, this will be blank. This will only be provided if core diameter data has been uploaded to the Platform.
core_diameter_mm	The core diameter in millimetres associated with the drill bit. If there are no coherent rock pieces in the interval, this will be blank. This will only be provided if core diameter data has been uploaded to the Platform.
groundtruth_rqdm	Sum of site measured length of coherent rock pieces longer than 100mm
groundtruth_rqd	Sum of site measured length of coherent rock pieces longer than 100mm divided by interval length, multiplied by 100
driller_breaks_count	Number of drillers breaks (mechanical breaks) detected
coherent_rock_length	Length of coherent/whole core in metres
incoherent_rock_length	Length of incoherent/broken rock in metres
coreloss_length	Total recorded core loss in metres
non_rock_length	Combined length of empty tray and core block in metres
timestamp	Time of model prediction
version	A model version identifier

*Only included if project depths are in feet.

Product Limitations

Limitations	Comments
Does not account for rock strength / soundness	As this product only uses Coherent Rock and Drillers Break models, it does take the strength of the rock into account. It will therefore over estimate RQD in areas of weathered / low strength rock.
Reliance on drillers break mark detection	Mechanical breaks are very difficult to classify from a photo, therefore Datarock’s RQD relies on these breaks being visually identified, usually with a cross adjacent to the break. If mechanical breaks are not identified, the result will generally be higher than a site logged RQD.

Limitations

Comments

Does not account for rock strength / soundness

As this product only uses Coherent Rock and Drillers Break models, it does take the strength of the rock into account.

It will therefore over estimate RQD in areas of weathered / low strength rock.

Reliance on drillers break mark detection

Mechanical breaks are very difficult to classify from a photo, therefore Datarock’s RQD relies on these breaks being visually identified, usually with a cross adjacent to the break.

If mechanical breaks are not identified, the result will generally be higher than a site logged RQD.

Document Version

Version	Date	Author	Rationale
1	6 Sep 2022	S Johnson	Initial release
2	30 Jan 2023	S Johnson	Update mechanical break description
3	29 January 2024	S Johnson	Update to include depth in feet
4	8 April 2024	N Pittaway	Minor edits to CSV tables
5	30 April 2024	S Johnson	Included 2x core diameter method