2008-01-16_APPLICATION CORRESPONDENCE - C2008086 ‎(3)‎

• Permit No: C2008086
• IBM Index Class Name: Application Correspondence
• Doc Date: 1/16/2008
• Doc Name: Preliminary Draft Environmental Impact Statement/Subsidence
• Media Type: D
• Archive: No

®RAFT
Table 1. Predicted Maximum Subsidence for Selected Panels, McClane Canyon Mine
Panel Panel Panel Ratio Lmax Robbed Lmax Super- Panel Predicted
(dent. Width Mid-Depth Panel Pillar (Pillar Ht Critical Correction Smax
feet feet Width/ Width /Panel Subsidence Factor feet
(meters) (m) Depth (feet) Depth) (feet)
1 465 900 0.517 19.15 20 9.576 35.5% 0.55 1.95
(142m) (274m) (3.55)
2 570 400 1.425 9.89 25 3.954 24.9% 0.61 1.52
(174m) (122m) (2.49)
3 535 500 1.070 11.97 30 3.990 25.0% 0.81 2.02
(163m) (152m) (2.50)
4 515 800 0.644 27.86 20 13.93 39.9% 0.64 2.56
(157m) (2.44m) (3.99)
5 340 355 0.958 7.77 34 2.285 18.4% 0.85 1.56
(104m) (108m) (1.84)
NOTES: Assumed 160 PCF overburden density, 10-foot mining height, stump pillar widths are minimums after pillar robbing on the
retreat from the panel, all values approximate?
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