PERMFILE52282

• Permit No: C1996083
• IBM Index Class Name: Permit File
• Doc Date: 7/3/2007
• Doc Name: 03/29/2007 Stability Evaluation of Proposed Coal Wastepile No. 3 Report, Buckhorn Geotech
• Section_Exhibit Name: Volume XI Coal Mine Waste Disposal Area No. 3
• Media Type: D
• Archive: No

Table 9. Summary of Stability Evaluations
Maximum Critical Factor of Safety`
Cross Gob Gob Height' Total Stress Effective Stress
Sectionf Geometry= (ft) Analysis Analysis
1.68 (circular)
2.5H:1 V (0-95') 95 1.68 (high gw) 1.53
1.53 (block)
2.5H:1 V (0-100') 100 1.58 (circular) 1 52
1.46 (block)
2.SH:1V (0-50') 1.64 (circular)
3H:1V (50-105') 105 1.64 (high gw) 1.52
1.52 (block)
Section A
2.SH:1 V (0-50') 110 1.57 (circular) 1.53
3H:1 V (50-110') 1.44 (block)
2.SH:1V (0-50') 1.70 (circular)
3.SH:1V (50-110') 110 1.70 (high gw) 1.52
1.54 (block)
1.59 (circular)
3H:iV (0-115') 115 1.59 (high gw) 1.81
1.56 (block}
2.SH:1V (0-67') 95 1.98 (circular) 1 52
2.05 (block)
2.SH:1V (0-50') 105 1.95 (circular) 1 76
•
3H:1 V (50-77') 2.05 (block)
Section B
2.SH:1V (0-50')
110 2.14 (circular)
1.70
3.SH:1V (50-77') 2.12 (block)
3H:1V (0-115') 115 1.82 (circular) 1 82
1.81 (block)
2.5H:1V (0-93') 95 1.77 (circular) 1 52
1.64 (block)
2.SH:1V (0-50') 105 1.91 (circular) 1 51
3H:1 V (50-93') 1.79 (block)
Section C
2.SH:1V (0-50')
110 2.09 (circular)
1.52
3.5H:1V (50-86') 1.91 (block)
3H:1V (0-115') 115 2.16 (circular) 1 82
2.17 (block)
Notes:
1. Cross secton locations indicated on Drawing 2.
2. Indicates gob slopes for various heights. Height measured from downgradient toe of gob pile to crest or gob pile
for each particular section, as indicated in Appentlix E. A 15-foot wide bench 50 vertical feet from the tce rs
included in all analyses.
3. Maximum gob height measured from downgradient toe to crest of pile at maximum section (Section A).
4. Factor of safety by Spencefs procedure.
t
Bowie Gob Pile No. 3 stability report
Project N06~481-002
Page 14 of t7