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 3
MAXIMUM SUBSIDENCE PARAMETERS FOR
APACHE ROCKS WEST MINING AREA(')
E-Seam Mining B-Seam Mining Sum of E and B-Seam
Mining
Parameter Panels E10-E12(t=10 to 14 ft) Panels B72-B13A(t=12 ft) Sum of E&B Panels
\/\//d;(z) Max E10-E12: 1080/400 2.70 B12-13A: 950/750 1.27
Min 1080/1100 0.98 950/1300 0.73
t=10ft t=14ft t=12ft t=10ft t=14ft
(3) Max 4.0 5.6 4.8 -- --
S°°-a°° t Min 1.0 1.4 1.2
(asp S.dt) Max 0.4 0.4 0.4
Min 0.1 0.1 0.1 -- --
Max 8.0 11.2 9.6 17.6 20.8
Sm=a•t(4)
Min 6.0 8.4 7.2 13.2 15.6
(a Sm/t)
Max 0.8 0.8 0.8 -- --
=
Min 0.6 0.6 0.6 -- --
Sm/d(5) Max 0.020 0.028 0.013 0.033 0.041
Min 0.005 0.008 0.006 0.011 0.013
Mm(2.2 to 2.3 Sm/d)(5)
Max 0.046 0.064 0.029 0.055 0.077
Min 0.012 0.017 0.012 0.014 0.020
Em(in terms of S,n/d)(7) Max 0.028 0.039 0.018 0.046 0.057
(1.2 to 1.4 Sm/d) Min 0.007 0.009 0.007 0.013 0.016
-Em(in terms of Sm/d)(7) Max -0.030 -0.042 -0.019 -0.049 -0.061
(-1.2 to-1.5 Sm/d) Min -0.007 -0.009 -0.007 -0.013 -0.016
1 Max 100 100 100 100 100
Maximum Crack Depth Min 50 50 50 50 50
8) Max 150 150 150 150 150
2
Min 75 75 75 75 75
Break Angle(s)
Max 5° 5° 5° 5° 5°
Min 0° 0° 0° 0° 0°
Angle of Draw(9)
Max 19° 19° 19° 190 19°
Mini 14° 14° 14° 14° 14°
(1)Maximum tilt and strain parameters apply only to ground surfaces with slopes less that 30 percent;values may be greater on slopes steeper
than 30 percent.
(2)All panels are numbered according to planned panel identifications.
(3)Subsidence and subsidence factor above chain pillars.
(4)
Subsidence(maximum vertical displacement)above longwall panel centers,based on planned coal extraction thickness listed.
(5)Ratio of the range of maximum vertical displacement to overburden depth range for the longwall panels.
(5)Maximum range of tilt in terms of Sm/d;values of 2.2 to 2.3 Sm/d are obtained from the graph in Figure 5.
(7)Maximum range of horizontal strain in terms of Sm/d;values for tensile(positive)strain of 1.2 to 1.4 Sm/d and compressive(negative)strain
of-1.2 to-1.5 Sm/d are obtained from the graph in Figure 5.
(8)Maximum crack depth(in feet)in bedrock predicted to locally occur on or near steep slopes and ledges in the Minnesota Creek and Lick
Creek drainage areas and above barrier pillars and rigid chain(gate road)pillars. The first depth range(1)is for bedrock sloping less than,
or equal to,30 percent;the second depth range(2)is for slopes more than 30 percent.Add 5 to 15 feet where thick,brittle sandstones
occur in ridges and near cliffs.No cracks are predicted to occur in alluvium. No cracks are predicted to occur at the surface of colluvium
thicker than about 10 feet.
(1)Angle measured from a vertical reference.
G:\WWE\831-032\921\Engr\Exhibit60E\Tables\ Wright Water Engineers,Inc. Calc By:MO
Table 3 Apache Rocks.xlsx Decemner 30,2020 Chkd By:JMK