PERMFILE45235

• Permit No: C1980007
• IBM Index Class Name: Revision
• Doc Date: 12/2/2004
• Doc Name: Exhibit 60D Certification2004 Geologic Hazard Field Observations for the South of Divide Mining Area
• Type & Sequence: PR10
• Media Type: D
• Archive: No

2004 Geologic Hazard Field Observations
South of Divide Mining Area
•
TABLE 1
Maximum Subsidence Parameters For
South Of Divide Mining Area t'~
~~
L
r1
LJ
Parameter Panels E1 - E4 (t = 8 to 14 ft) Panels ES - E8 (t = 12 to 14 ft) Panel E9 (t = 12 to 14 ft)
W/d: Max
Min E1: 1080 / 625 = 1.73
1080 / 1425 = 0.76 E5: 1080 / 500 = 2.16
1080 / 1100 = 0.98 E9: 1080 / 500 = 2.16
1080 / 550 = 1.96
Max
Min E2: 1080 / 400 = 2.70
1080 / 1100 = 0.98 E6: 1080 / 500 = 2.16
1080 / 1200 = 0.90
Max
Min E3: 1080 / 500 = 2.16
1080 / 1100 = 0.98 E7: 1080 / 550 = 1.96
1080 / 1250 = 0.86
Max
Min E4: 1080 / 400 = 2.70
1080 / 1025 = 1.05 E8: 1080 / 675 = 1.60
1080 / 825 = 1.31
t=8ft t=14ft t=12ft t=14 t=12ft t=14
S°P=a~•tt31
(aw=S~It) 0.80 to2.4ft
(0.1 to 0.3) 1.4 to4.2ft
(0.1 to 0.3) 1.2 to3.6ft
(0.1 to 0.3) 1.4 to4.2ft
(0.1 to 0.3) 1.2ft
(0.1) 1.4ft
(0.1)
Sm=a•tt4t
(a = Smlt) 4.8 t06.4ft
(0.6 to 0.8) 8.4 t011.2ft
(0.6 to 0.8) 7.2 to 9.6
(0.6 to 0.8) 8.4 t011.2ft
(0.6 to 0.8) 8.4 t09.6ft
(0.7 to 0.8) 9.S t011.2ft
(0.7 to 0.8)
Sm/d l~ 0.00377 to
0.0160 0.00590 to
0.0280 0.00576 to
0.0192 0.00672 to
0.0224 0.01527 to
0.0192 0.01782 to
0.0224
Mm (2.2 to 2.3 Smld) t8~ 0.007 to 0.037 0.013 to 0.064 0.013 t0 0.044 0.015 t0 0.052 0.034 t0 0.044 0.039 to 0.052
Em (in terms of Sm/d) i'~
(1.2 to 1.4 Smld) 0.004 to 0.022 0.007 to 0.039 0.007 to 0.027 0.008 to 0.031 0.018 to 0.027 0.021 to 0.031
-Em (in terms of Smld) in _0 004 SO -0.024 -0.007 20 -0.042 -0.007 SO -0.029 -0.008 to -0.034 -0.018 to -0.029 -0.021 to -0.034
Maximum Crack 1 5-10ft 5-15ft 5-10ft 5-15ft 5-10ft 5-15ft
DepthrBl 2 10-20ft 15-35ft 15-25ft 15-35ft 15-25ft 15-35ft
Break Angle IBI 0 - 5° 0 - 5° 0 - 5° 0 - 5° 0 - 5° 0 - 5°
Angle of Draw tB~ 10 - 20° 10 - 20° 10 - 20° 10 - 20° 10 - 20° 10 - 20°
t~l Maximum tilt and strain parameters apply only to ground surfaces with slopes less that 30%; values may be greater on
slopes steeper than 30 percent.
Isl All panels are numbered according to planned panel iden8fica8ons.
tai (Subsidence and subsidence factor above chain pillars.
t`~ Subsidence (maximum vertical displacement] above longwall panel centers, based on planned coal extraction thickness
listed.
t~ Ratio of the range of maximum vertical displacement to overburden depth range for the nine planned longwall panels.
I8I Maximum range of Blt in terms of Sm/d; values of 2.2 to 2.3 Sm/d are obtained from the graph in Figure 5 (Exhibit 60 B).
m 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 S,dd are obtained from the graph in Figure 5 (Exhibit 60B).
I8I 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 steep bedrock sloping and cliffs more
than 30 percent. No cracks are predicted to occur in alluvium. No cracks are predicted to occur at the surface of colluvium
thicker than about 10 feet.
t9I Angle measured from a vertical reference.
831-032.621 Wright Water Engineers, Inc. Page 18
November 2004