2013-09-27_REPORT - C1980007 ‎(4)‎

• Permit No: C1980007
• IBM Index Class Name: REPORT
• Doc Date: 9/27/2013
• Doc Name: Spring 2013 Subsidence Monitoring Report
• From: Wright Water Engineers, Inc
• To: DRMS
• Permit Index Doc Type: Subsidence Report
• Email Name: JRS
• Email Name: DIH
• Media Type: D
• Archive: No

0.1
CI) 0.2
11
CU
0.3
Q 0.4
f—
Q 0.5
LL.
W 0.6
Z 0.7
W
0 0.8
tb 0.9
U) 1.0
�- Somerset Mine
�n
El- -,—West Elk Mine
NCB, 1975 —�
0.2 0.4 0.6 0.8 1
W/d
-- O
O
❑o
Figure C. Graph showing subsidence factors (a = S,,, /t) versus mining panel width to depth
ratios (W /d) for the West Elk longwall mine (squares), 1972 to 1976 Somerset room - and - pillar
mine (circles), and the York Canyon, New Mexico longwall mine (diamonds), along with the
average National Coal Board (NCB) longwall curve. Topographic effects on subsidence factors
for the York Canyon, New Mexico longwall mining area (upper point of measurement was in a
deep draw; middle point was on an isolated ridge; lower point is maximum for area).