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 15
Design Mining Height, ft
Depth of Cover, ft 7 7.5 8 8.5 1 9 9.5 I 10 10.5 11 111.5 1 12 I 12.5 1 13
190 20.51 21.2 21.9 22.51 23.1 23.71 24.3 24.9 25.41 25.91 26.51 27.01 27.5
210 23.11 23.9 24.6 25.41 26.1 26.81 27.4 28.1 28.71 29.3 29.9 30.5 31.1
230 25.71 26.6 27.4 28.21 29.0 29.81 30.6 31.3 32.11 32.8 33.5 34.1 34.8
250 28.01 29.2 30.2 31.11 32.0 32.91 33.8 34.6 35.41 36.2 37.0 37.7 38.5
270 28.01 30.0 32.0 34.01 35.0 36.01 36.9 37.9 38.81 39.6 40.5 41.3 42.2
290 28.0 30.0 32.0 34.0 36.0 38.01 40.0 41.1 42.1 43.1 44.0 45.0 45.9
310 30.0 31.1 32.1 34.0 36.0 38.01 40.0 42.0 44.0 46.0 47.6 48.6 49.6
330 32.3 33.4 34.5 35.5 36.6 38.0 40.0 42.0 44.0 46.0 48.0 50.0 52.0
350 34.5 35.7 36.8 38.0 39.1 40.2 41.2 42.2 44.0 46.0 48.0 50.0 52.0
370 36.7 38.0 39.2 40.4 41.6 42.8 43.9 45.0 46.1 47.1 48.2 50.0 52.0
390 38.9 40.3 41.6 42.9 44.2 45.4 46.6 47.8 48.9 50.1 51.2 52.2 53.3
410 41.1 42.5 44.0 45.4 46.71 48.0 49.3 50.6 51.8 53.0 54.2 55.3 56.4
430 43.3 44.8 46.4 47.81 49.31 50.7 52.0 53.3 54.6 1 55.9 57.2 58.4 59.6
Coal strength, psi 821 Mining width, ft 11.50 No. web pillars 19
Pillar widths in italics have width-to-height ratios of 0.8
60
55 �+
+� Mining
Height,
ft
50 � 7
t�
F I� 7.5
❑ �fi
mac-8
x 45
8.5
t
w 40 9.5
10
m
r fi 10.5
35
L F
W 11.5
30
r �12
- r
13
25
20
190 210 230 250 270 290 310 330 350 370 390 410 430
DEPTH OF COVER, ft
Figure 5b. Barrier Pillar Design Chart-Collom D1/D2 Seam
Agapito Associates, Inc.