2008-03-21_PERMIT FILE - C1980007A ‎(8)‎

• Permit No: C1980007A
• IBM Index Class Name: Permit File
• Doc Date: 3/21/2008
• Section_Exhibit Name: Exhibit 60E Subsidence Evaluation for the South of Divide & Dry Fork Mining Areas
• Media Type: D
• Archive: Yes

TABLE 1
MAXIMUM SUBSIDENCE PARAMETERS
FROM WEST ELK MINE SUBSIDENCE MONITORING NETWORK

Notes:
(1) Numerical curvature values are in radians per foot (rad/ft).
(2) Maximum crack depth is projected for hard, brittle sandstones; depth is expected to be much less, or
non-existent, in soft, ductile shales and claystones.
(3) Measurement from vertical reference.
(4) Measurement takes into account influence of development entries, chain pillars, and prior F-Seam
mining.
Parameter Longitudinal Profile Longitudinal Profile No. Transverse Profile
So. End 1 NW LW End 1 NW LW Above 2,3 NW LW
W/d 750/1240=0
6 750/1350=0
56 2 NW: 750/1000=0.75 3
. . NW: 750/900=0.83
app=Scp/t N/A N/A 0.20 to 0.35
a=Sm/t 6.94/12=0.58 6.06/11.5=0.53 2 NW: 0.62 3 NW: 0.58
Sm/d 0.005597 0.004489 2 NW: 0.00729 3 NW:
0.00762
Sm/d2 0.000004514 0.000003325 2 NW: 0.00000729 3 NW:
0.00000847
Mm 0.015 (2.7•Sm/d) 0.014 (3.1 •Sm/d) 2 NW: 0.014 3 NW: 0.021
(1)
Cm 0.000065 (14.4•Sm/d2) - 0.000060 (18.0•Sm/d2) - 2 NW: 0.00022 3 NW:
0.00014 2 NW: -0.00025 3
0.000111 (-24.6•Sm/d2) 0.000066 (-19.9-Sm/d2) NW: -0.00012

Em 0.0070 (1.25•Sm/d) -0.0047 0.0058 (1.3•Sm/d) -0.0009 (- 2 NW: 0.0102 3 NW: 0.0085
2 NW: -0.0236 3 NW: -
(-0.8-Sm/d) 0.2•Sm/d) 0.0307
Maximum Crack
(2)
80 feet
100 feet
50 feet
Depth
(3)
l 32percent Slope -9° Slope 42percent Slope Y Slope in -
Break Ang
e in same Direction as tilt opposite Direction to tilt
Angle of Draw (3) 17°(4) 15°(4) -
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