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

TABLE 3.4.A.21
PILLAR SIZE AND FACTOR OF SAFETY-AREA IV-
LONGWALL MINING
r1
+ = Lagging cave
April 1989

Factor Recom me nded
Pillar Analyzed Pillar of Pi ll ar
Width x Length Safety Widtli x Length
(ft x ft) (ft x ft)
~B SEAM --- ---- ------
Mains 60 x 120 2.1 60 x 100
Barrier 180 x 700 2.7 150 x 700
Gate 30 x 100 1.2 30 x 100
Bleeder 8U x 100 1.8-1.3+ 80 x 100
Starting
room barrier 100 x .160 1.2+ 100 x 160
E SEAM -- - -------- - --- -- - ---I
Mains 60 x 120 2.5 60 x 100
Barrier N/A tl/A 210 x 700
Gate 30 x 100 1.5 30 x 100
Bleeder 60 x 100 1.4+ 60 X 100
Starting
oom barrier
r 80 x 160 1.5` 160 x 160
~
-
F SEAM ---- -- --- ---- -- -...---- ~
Mains 60 x 120 7..9 60 x 100
Barrier N/A N/A 230 x 700
Gate 30 x 100 2.0 -?.5 to 30 x 100
Bleeder 60 x 100 1.8+ 50 x 100
Starting
room barrier 70 x 160 1.7+ 180 x 160