How to drape and digitise underground wall mapping in Surpac

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As an underground geologist, one of the weekly jobs maybe to map the structures and lithological contacts in the development drives. This information can then be used to update grade control and resource models, geotechnical models, and help with future mine planning.

In this blog we will discuss how we can bring the sketched wall mapping into Surpac.

 

1. Prior to mapping the drive, you will have measured off from a survey wall/back/roof station to the start of the portion of the drive that is to be mapped and this distance will have been noted on the mapping sheet.

2. In Surpac, open up the drive strings and the survey station database.Using Inquire>bearing and distance between 2 points, using trial and error, measure of the distance that was noted on the mapping from the survey station and a point on the floor string until you get the approximate distance.

Break the segment using edit>segment>break. Then delete the portion that is not required using edit>segment>delete.You now have the drive strings for the portion of the wall that was mapped.

 

 

 

3. The exact point the mapping started from now needs to be located. Using Inquire>bearing and distance between 2 points, change the snap mode to line by activating the bearing and distance function, then right clicking on the mouse and selecting line.

 

 

Once you have measured off the exact distance, check the snap mode is still set to line and digitize a new point using a different string number. Create>digitise>properties and set the string to 1. Create>digitise>new point

 

 

 

4. Once the starting point has been created, the reference marks (which will be used to register the mapping) now need to be measured off and digitised in. These marks will have been defined on the wall mapping and may be inflection points in the drive or set meter marks on the wall.

To do this we use the function Inquire>Segment length to measure off the distance for each of the reference marks. When you have located the 2nd reference mark (the first being the starting point of the mapping) check the snap mode is set to line, create>digitise>properties and set the string to 1 or the string number used in step 3. Create>digitise>new point.

Repeat this process until all the floor reference marks are digitised. Then digitise a point on the shoulder string above each of the floor reference marks. See the pictures below.

 

 

The pink points on the mapping sheet are now digitised on the wall string.

 

 

 

5. Save the string file.

6. Using solids>triangulate>between segments, triangulate between each of the segments.

 

 

7. If you want the section to be exactly in the plane of the dtm, you can use quick planes to set up an oblique section.

 

 

 

 

 

Click on the dynamic grid to bring the graphics window into the correct plane

 

If you need to turn the dtm around due to the wall being draped you can use this function. Reverse view direction. 

 

TURN off the dynamic grid.

 

8. You will have already scanned the mapping into the computer and saved it as a jpeg. We now need to register/drape the scanned mapping onto the wall dtm. To do this you need to go File>image>drape. Select the dtm, then fill in the form with the name of the rgf file and the image file.

 

 

9. Follow the instructions at the bottom of the screen highlighted in yellow and Register the known points on the image with the known points on the dtm. Note: It’s important that you follow the instructions at the bottom of the screen.

 

 

And apply.

 

 

 

10. Create a new layer and set this as the working layer. 

 

 

11. Using the functions from step 3, set the string colour, change the snap mode to triangle and start digitising the features from the wall mapping. Remember to start a new segment for each new feature.

 

 

In this example Faults are dark blue, bedding foliation are light blue, orange are joints, magenta are shears, apple green are lithological contacts, yellow are mineralisation pods, and white are the structural readings.

 

12. To digitise in the structural readings, create a point at each reading location, then edit>point>properties, and put the feature code into D1, Dip into D2, and Dip Direction into D3.

 

 

 

 

 

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Kim Ferguson-Thomas

Kim Ferguson-Thomas

Technical Customer Support Consultant, GEOVIA at Dassault Systèmes
Kim Ferguson-Thomas has more than 20 years’ experience as a geologist in the mining industry, working in exploration, underground and open-cut mines within Australia.