Rock Quality Designation (RQD)
- Sam Johnson
- Nathanael Pittaway
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.
Contents
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. Â
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.
Â
RQD is then calculated based on the equation below.
Product Configuration Options
Configuration | Options |
|---|---|
Treatment of core loss | Core loss can be treated as either:
|
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 |
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:
ProjectID_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) |
predicted_rqdm (this will be removed after 30 June 2024, replaced by rqdm_10 below) | Sum of Datarock measured length (in metres) of coherent rock pieces longer than 100mm |
predicted_rqd (this will be removed after 30 June 2024, replaced by rqdm_10 below) | Sum of Datarock measured length of coherent rock pieces longer than 100mm divided by interval length |
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 |
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. 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.
Â
ProjectID_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) |
predicted_rqdm (this will be removed after 30 June 2024, replaced by rqdm_10 below) | Sum of Datarock measured length (in metres) of coherent rock pieces longer than 100mm |
predicted_rqd (this will be removed after 30 June 2024, replaced by rqdm_10 below) | Sum of Datarock measured length of coherent rock pieces longer than 100mm divided by interval length |
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 |
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. 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 |
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.
Â
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. |
Â
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 |
Â
Â