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.23
PILLAR SIZE AND FACTOR OF SAFETY-AREA V-
LONGWALL MINING
April 1989

Factor Recommended
Pillar Analyzed Piller of Pillar
Width x Length Safety Width x Length
(ft x ft) (ft x ft)
E SEAM _ -~
Mains 60 x 120 1.9 60 x 120
Barrier 200 x 700 2.5 180 x 700
Gate 30 x 100 1.1 35 x 100
Bleeder 90 x 100+ 1.2 80 x 100
Starting
room barrier 110 x 700+ 1.3 100 x 700
F SEAM -- _ ---
Mains 60 x 120 2.1 60 x 120
Barrier 180 x 700 ?..7 230 x 700
Gate 30 x 100 1.3 30 x 100
Bleeder 80 x 100 1.8-1.3+ GO r. 100
Starting
room barrier 100 x 700 1.2 150 x 700
+ = Lagging cave
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