Fragmentation analysis - FAQs

How the rock size detection and filtering works when I edit the muckpile shape?

Strayos frag AI detects all the rocks sizes from the orthophoto of the whole dataset. When the boundary is detected / edited/ moved, Strayos filter out the rocks that are inside the boundary, and sort them based on diameters. From this rock sizes array, we are getting the value of D01, D10, D20...D80, D90. From the data we got from rock sizes, we calculate the Kuz-ram and Swebrec curves.

What does the rock size means?

The rocks that are detected by using AI technique are treated as a rectangles for size calculation. Each rock has two diameters: the long side and the short side. We are taking the average of these two diameters as rock size.

What does D01, D10 ,D50 and Dmax means?

D01: means the minimum rock size detected inside the boundary. (It usually the same for most boundaries, because the smallest diameter that we can get from an orthophoto image is the length of one pixel).

D10: means the rock size that is larger than 10% of all the rocks detected inside the boundary.

D50: means the rock size that is larger than 50% of all the rocks detected inside the boundary. (This is an important parameter for Kuz-ram and Swebrec modelling).

Dmax: means the maximum rock sizes that we detected inside the boundary. (We are not showing the value in the data table, but it is displayed in the graph table. This is also an important parameter for Kuz-ram and Swebrec modelling).

How does the n: Cunningham’s Uniformity index is calculated?

n: Cunningham’s Uniformity index. It is a constant parameter in Kuz-ram model. The value of n will determine the shape of the curve. Strayos has developed a approach to calculate the n value dynamically  from the post blast rock sizes statistics.

How does the b: Curve-undulation parameter is calculated?

b: Curve-undulation parameter. It is a constant parameter in Swebrec model. It determines the shape of Swebrew curve.  We are calculating b value  dynamically from the post blast rock sizes statistics

How is Sphericity calculated?

 Strayos draws a rectangle around each rock to calculate the size. Sphericity = long side of the rectangle / short side of the rectangle. This provides a more accurate method to generate sphericity index.