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 4
MAXIMUM SUBSIDENCE PARAMETERS FOR
SUNSET TRAIL MINING AREA(')
Parameter Panels SS1 -SS4 (t=9 to 14 ft)
W/d:(2) Max SS1 1080/770 1.40
Min 1080/ 1220 0.89
Max SS2 1080/650 1.66
Min 1080/ 1260 0.86
Max SS3 1080/390 2.77
Min 1080/ 1250 0.86
Max SS4 1080/350 3.09
Min 1080/ 1100 0.98
t=9ft t=14ft
SAP=a,P•t
(3) Max 2.7 4.2
Min 0.9 1.4
Max ax 0.3 0.3
Min 0.1 0.1
Sm=a,t(4)
Max 7.2 11.2
Min 5.4 8.4
(a=Sm/t)
Max 0.8 0.8
Min 0.6 0.6
Sm/d is>
Max 0.021 0.032
Min 0.004 0.007
Mm(2.2 t0 2.3 Sm/d)(6)
Max 0.047 0.074
Min 0.009 0.015
Em(in terms of Sm/d)(7) Max 0.029 0.045
(1.2 to 1.4 Sm/d) Min 0.005 0.008
-Em(in terms of Sm/d)(7) Max -0.031 -0.048
(-1.2 to-1.5 Sm/d) Min -0.005 -0.008
1 Max 10 15
Maximum Crack Min 5 5
Depth le) Max 35 35
2
Min 15 15
Break Angle(9)
Max 5° 5°
Min 0" 0°
Angle of Draw(9)
Max 19, 19,
Min 14' 14'
(')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. Because the tables provides for the full range of values,there is
no need to distinguish between Layouts A and B.
(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.
(6)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.
(9)Angle measured from a vertical reference.
G:\WWE\831-032\921\Engr\Exhibit 60E\Tables\ Wright Water Engineers,Inc. Calc By:MO
Table 4 Sunset Trail.xlsx December 30,2020 Chkd By:JMK