2001-12-11_PERMIT FILE - C1980007A ‎(2)‎

• Permit No: C1980007A
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Doc Name: By TOC Deleted
• Section_Exhibit Name: Exhibit 40 Geotechnical Analysis B & F Seams
• Media Type: D
• Archive: Yes

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TABLE 3.4.A.17
PILLAR SIZE AND FACTO}2 OF SAFETY-AREA II
-LONGWALL MINING
nNril 1yt39

Pillar
Analyzed Pillar
Width x Length
(ft x ft) Factor
of
Safety Recommended
Pillar
Width x Length
(ft x ft)
B SEAM
Mains 60 x 120 1.5 60 x 120
Barrier 200 x 700 2.2 180 x 700
Gate 30+ x 100 .9 35+ x 100
Bleeder 90 x 100 1.5-.9x 90 x 100
Starti~tg
room barrier
110
x
700
N/A-1.Ox
120
x
700
E SEAM --- ----- --
Maids 60 x 120 1.9 80 x 100
Barrier 200 x 700 2.5 280 x 700
Gate 30~ x 100 1.1 35+ x 100
Bleeder 90 x 100 1.7-1.7.+ 90 x 100
Starting
room barrier
N/A
N/A
200
x
700
F SEAM - ------- --...- --- ------ -
Mains 60 x 120 2.0 60 x 100
Barrier ].80 x 700 2.7 32.0 x 700
Gate 30 x 100 1. 7. 30 x 100
Bleeder 80 x 100 1.8 ^ 80 x 100
Starting
room barrier
N/A
N/A
240
x
700
+ = 9 ft mining height
x = lagging cave
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