2021-02-05_PERMIT FILE - C1980007A ‎(5)‎

• Permit No: C1980007A
• IBM Index Class Name: Permit File
• Doc Date: 2/5/2021
• Doc Name: SUBSIDENCE EVALUATION
• Section_Exhibit Name: Exhibit 60E Subsidence Evaluation for the South of Divide and Dry Fork Mining Areas
• Media Type: D
• Archive: Yes

TABLE 1
MAXIMUM SUBSIDENCE PARAMETERS
FROM WEST ELK MINE SUBSIDENCE MONITORING NETWORK
Parameter Longitudinal Profile Longitudinal Profile Transverse Profile
So. End 1 NW LW No. 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
asp=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 0.014 2 NW: 0.014
(2.7•Sm/d) (3.1•Sm/d) 3 NW: 0.021
Cm(l) 0.000065 0.000060 2 NW: 0.00022
(14.4•Sm/d2) (18.0•Sm/d2) 3 NW: 0.00014
-0.000111 -0.000066 2 NW: -0.00025
(-24.6-Sm/d2) (-19.9-Sm/d2) 3 NW: -0.00012
Em 0.0070 0.0058 2 NW: 0.0102
(1.25•Sm/d) (1.3•Sm/d) 3 NW: 0.0085
-0.0047 -0.0009 2 NW: -0.0236
(-0.8-Sm/d) (-0.2-Sm/d) 3 NW: -0.0307
Maximum 80 feet 100 feet 50 feet
Crack Depth(2)
Break Angle(3) 32percent 42percent Slope - -
Slope- 3° Slope in opposite
-9° Slope in same Direction to tilt
Direction as tilt
Angle of 170(4) 15°(4) -
DraW(3)
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.