2021-05-27_PERMIT FILE - C1981019A ‎(7)‎

• Permit No: C1981019A
• IBM Index Class Name: Permit File
• Doc Date: 5/27/2021
• Doc Name: Addendum Collom and South Taylor Highwall Mining Geotechnical Design
• Section_Exhibit Name: Volume 20 Exhibit 27 Item 7
• Media Type: D
• Archive: Yes

Mr. Lee Sampson
April 23, 2021
Page 18
Design Mining Height, ft
Depth of Cover, ft 4 1 4.33 4.67 5 1 5.33 5.67 1 6 6.33 6.67 I 7 7.33 17.67 8
140 10.41 10.7 11.1 11.41 11.8 12.11 12.4 12.7 13.01 13.2 13.51 13.8 14.0
170 13.01 13.5 14.0 14.41 14.9 15.31 15.7 16.1 16.51 16.9 17.21 17.6 17.9
200 15.71 16.3 16.9 17.51 18.0 18.61 19.1 19.6 20.01 20.5 21.01 21.4 21.8
230 16.01 17.4 18.7 20.01 21.2 21.81 22.4 23.0 23.61 24.2 24.71 25.3 25.8
260 17.71 18.4 19.1 20.01 21.4 22.71 24.0 25.4 26.71 27.8 28.51 29.1 29.8
290 20.0 20.8 21.6 22.3 23.0 23.7 24.4 25.4 26.7 28.0 29.4 30.7 32.0
320 22.3 23.2 24.1 24.9 25.7 26.5 27.3 28.0 28.7 29.4 30.1 30.7 32.0
350 [24.6 25.6 26.6 27.5 28.4 29.3 30.1 31.0 31.8 32.5 33.3 34.0 34.8
380 28.0 29.1 30.1 31.1 32.1 33.0 33.9 34.8 35.7 36.5 37.4 38.1
410 30.5 31.6 32.7 33.8 34.9 35.9 36.9 37.9 38.8 39.7 40.7 41.5
440 32.9 34.2 35.4 36.5 37.7 38.8 39.9 40.9 42.0 43.0 44.0 44.9
470 35.3 36.7 38.0 39.2 40.5 41.7 42.8 44.0 45.1 46.2 47.3 48.3
500 37.7 39.2 40.6 41.9 43.3 44.6 45.8 47.1 48.3 49.4 50.6 51.7
Coal strength, psi 900 Mining width, ft 11.50 No. web pillars 19
Pillar widths in italics have width-to-height ratios of 0.8
55
50
+ Mining
+ Height,
ft
45
r � 4
I+
_ 4.33
p 40
+� w 4.67
J �5
a 35 +r tl+ -5.33
r
a +I� ++ 5.67
mlAle
30 6
r + --49-6.33
d' J + J `
25 - 6.67
LU
X 7
1
-7.33
20
7.67
8
15
10
140 170 200 230 260 290 320 350 380 410 440 470 500
DEPTH OF COVER, ft
Figure 6b. Barrier Pillar Design Chart-Collom E2 Seam
Agapito Associates, Inc.