2025-05-05_PERMIT FILE - C1981010 ‎(32)‎

• Permit No: C1981010
• IBM Index Class Name: Permit File
• Doc Date: 5/5/2025
• Doc Name: Inwall HWM Sequence Analysis
• Section_Exhibit Name: Appendix X-II 534-61
• Media Type: D
• Archive: No

Tonia Perkins
July 31, 2024
Page 5
Agapito Associates, Inc.
Figure 2(b). Barrier Pillar Design Table and Chart for the M Seam in N-Pit
Design
Depth of Cover, ft 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8
80 4.7 5.1 5.5 5.7 6.0 6.3 6.6 6.8 7.0 7.2 7.4 7.6 7.8
95 5.6 6.1 6.7 7.1 7.5 7.9 8.2 8.6 8.9 9.2 9.4 9.7 9.9
110 6.6 7.3 7.9 8.5 9.0 9.5 9.9 10.3 10.7 11.1 11.5 11.8 12.1
125 7.6 8.5 9.2 9.9 10.5 11.1 11.6 12.1 12.6 13.1 13.5 13.9 14.3
140 8.0 9.6 10.5 11.3 12.0 12.7 13.3 13.9 14.5 15.0 15.6 16.1 16.5
155 8.2 10.0 11.8 12.7 13.5 14.3 15.1 15.7 16.4 17.0 17.6 18.2 18.8
170 9.1 10.1 12.0 14.0 15.1 16.0 16.8 17.6 18.3 19.0 19.7 20.4 21.0
185 10.0 11.1 12.1 14.0 16.0 17.6 18.5 19.4 20.2 21.0 21.8 22.5 23.3
200 10.9 12.1 13.2 14.2 16.0 18.0 20.0 21.2 22.1 23.0 23.9 24.7 25.5
215 11.8 13.1 14.3 15.4 16.5 18.0 20.0 22.0 24.0 25.0 26.0 26.9 27.8
230 12.6 14.1 15.4 16.6 17.8 18.8 20.0 22.0 24.0 26.0 28.0 29.1 30.0
245 13.4 15.0 16.5 17.8 19.0 20.2 21.3 22.3 24.0 26.0 28.0 30.0 32.0
260 14.2 15.9 17.5 18.9 20.3 21.5 22.7 23.8 24.9 26.0 28.0 30.0 32.0
Coal strength, psi 766 Mining width, ft 11.50 No. web pillars 9
Pillar widths in italics have width-to-height ratios of 0.8
Mining Height, ft
0
5
10
15
20
25
30
35
0 50 100 150 200 250 300REQUIRED BARRIER PILLAR WIDTH, ft DEPTH OF COVER, ft
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
Mining
Height,
ft