“…Each image is comprised of four channels, similar to the RGB (red, green, blue) channels in a typical image, however in this case the channels are GEO, SUPCL, FREEZE, and DISP. The predicted tunnel liner yield is a categorical output, also digitized from the GMPs, and characterized by failed rock bolts, spalled shotcrete, and compressed yield packs (Morgenroth et al, 2020): Class 0 is no yield, Class 1 is yield requiring minor repair, Class 2 is yield requiring major repair, and Class 3 is yield requiring total tunnel reprofiling. The Cigar Lake Mine CNN is trained on a subset of GMP images and then tested on the subsequent GMP image, to simulate prediction of tunnel liner yield forward in time, i.e.…”