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 8
Agapito Associates, Inc.
Figure 3(b). Barrier Pillar Design Table and Chart for the Q Seam in N-Pit
Design
Depth of Cover, ft 7 7.5 8 8.5 9 9.5 10 10.5 11 11.5 12 12.5 13
110 10.6 10.9 11.2 11.5 11.7 12.0 12.3 12.5 12.7 12.9 13.2 13.4 13.6
130 13.2 13.6 14.0 14.3 14.7 15.0 15.4 15.7 16.0 16.3 16.6 16.9 17.1
150 15.8 16.3 16.7 17.2 17.6 18.1 18.5 18.9 19.3 19.7 20.1 20.4 20.8
170 18.4 19.0 19.5 20.1 20.6 21.2 21.7 22.2 22.6 23.1 23.6 24.0 24.4
190 21.0 21.7 22.4 23.0 23.7 24.3 24.9 25.5 26.0 26.6 27.1 27.6 28.2
210 23.6 24.4 25.2 26.0 26.7 27.4 28.1 28.8 29.4 30.1 30.7 31.3 31.9
230 26.2 27.2 28.0 28.9 29.7 30.5 31.3 32.1 32.8 33.6 34.3 35.0 35.6
250 28.0 29.9 30.9 31.8 32.8 33.7 34.5 35.4 36.2 37.1 37.9 38.6 39.4
270 28.0 30.0 32.0 34.0 35.8 36.8 37.8 38.7 39.7 40.6 41.5 42.3 43.2
290 28.3 30.0 32.0 34.0 36.0 38.0 40.0 42.0 43.1 44.1 45.1 46.0 47.0
310 30.4 31.5 32.6 34.0 36.0 38.0 40.0 42.0 44.0 46.0 48.0 49.7 50.8
330 32.5 33.7 34.9 36.0 37.1 38.2 40.0 42.0 44.0 46.0 48.0 50.0 52.0
350 34.5 35.8 37.1 38.4 39.6 40.7 41.9 43.0 44.0 46.0 48.0 50.0 52.0
Coal strength, psi 850 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
10
20
30
40
50
60
0 50 100 150 200 250 300 350 400REQUIRED BARRIER PILLAR WIDTH, ft DEPTH OF COVER, ft
7.0
7.5
8.0
8.5
9.0
9.5
10.0
10.5
11.0
11.5
12.0
12.5
13.0
Mining
Height,
ft