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 6
Design Mining Height, ft
Depth of Cover, ft 6 7.25 8.5 9.75 1 11 12.25 I 13.5 14.75 16 1 17.251 18.5 1 19.751 21
100 8.41 9.1 9.6 10.21 11.0 12.31 13.5 14.8 16.0 17.3 18.5 19.8 21.0
140 13.0 14.1 15.1 16.0 16.9 17.7 18.4 19.1 19.7 20.4 20.9 21.5 22.0
180 17.6 19.2 20.7 22.1 23.4 24.5 25.7 26.7 27.7 28.7 29.6 30.5 31.3
220 22.3 24.4 26.4 28.2 29.9 31.5 33.0 34.5 35.8 37.2 38.4 39.7 40.8
260 24.3 29.0 32.1 34.4 36.5 38.5 40.4 42.3 44.0 45.7 47.4 48.9 50.5
300 26.9 29.8 34.1 39.0 43.1 45.6 47.9 50.1 52.3 54.4 56.4 58.3 60.2
340 30.5 33.8 36.9 40.0 44.4 49.0 54.0 58.0 60.6 63.0 65.4 67.7 69.9
380 34.4 37.9 41.4 44.7 47.9 51.0 55.2 59.6 64.0 69.0 74.0 77.1 79.7
420 38.5 42.3 45.9 49.6 53.2 56.7 60.0 63.3 66.7 71.3 75.8 80.3 84.7
460 42.4 46.8 50.81 54.5 58.5 62.4 66.21 69.8 73.4 76.8 80.2 83.7 88.4
500 46.5 51.2 55.7 59.8 63.8 68.1 72.3 76.3 80.3 84.2 87.9 91.7 95.3
540 50.5 55.7 60.5 65.1 69.3 73.8 78.4 82.8 87.2 91.5 95.7 99.8 103.8
580 54.5 60.1 65.4 70.3 75.0 79.5 84.5 89.31 94.11 98.81 103.4 107.9 112.3
Coal strength, psi 900 Mining width, ft 11.50 No. web pillars 19
Pillar widths in italics have width-to-height ratios of 1.0
116
112
108
104
100 Mining
96 Height,
ft
92
88
w
84 t 6
= 80 7.25
76
72
68 - +9.75
J �T
a 64 - - 11
w 60 = 12.25
W 56 +
m 52 + 13.5
u9 48 += f 14.75
0 44 = 16
LU 40
17.25
36
32 - s - -18.5
28 - - 19.75
24 _ - 21
20 =
16 - -
12 ------09
-r
8
100 140 180 220 260 300 340 380 420 460 500 540 580
DEPTH OF COVER,ft
Figure 2b. Barrier Pillar Design Chart-South Taylor G78 Seam
Agapito Associates, Inc.