1987-12-01_PERMIT FILE - C1981017 ‎(284)‎

• Permit No: C1981017
• IBM Index Class Name: PERMIT FILE
• Doc Date: 12/1/1987
• Doc Name: Subsidence Study By Dr. Bruce Collins
• Section_Exhibit Name: Chapter IV Appendix IV-F-4
• Media Type: D
• Archive: No

16 -
Subsidence Ratio:• 0. 02 Location Relative to Mine Workings : approximate centerline,
lw 102 No. 1 mine, 740 ft ahead of face on 8/9/85 .
Discussion: in longwall 102 subsidence zone. Projected
maximum subsidence using ratio of 0. 30 : 3 .00 ft. See
Figure 18 .
Point No. : MC-14
Type : monitoring
Installed: 9/17-20/84 Surveyed: 8/85
Location (mine coordinate system) : 12516 .46N, 1961 . 14E
Original Elevation (ft) : 11,589 .56
Total Movement Since Installation (ft) : none detected
Estimated Coal Removed Within Subsidence Zone (ft) : none
Subsidence Ratio: --
Location Relative to Mine Workings: approximate centerline,
lw 102 No. 1 mine, 918 ft ahead of face on 8/9/85 .
Discussion: ahead of longwall 102 No. 1 mine subsidence zone
on date surveyed. See Figure 19.
Point No. : MC-15
Type : monitoring
Installed: 9/17-20/84 Surveyed: 8/85
Location (mine coordinate system) : 12677 .87N, 1846 .19E
Original Elevation (ft) : 11,576 .22
Total Movement Since Installation (ft) : none detected
• Estimated Coal Removed Within Subsidence Zone (ft) : none
Subsidence Ratio:--
Location Relative to .Mine Workings : approximate centerline ,
lw 102 No. 1 mine, 1 ,113 ft ahead of face on 8/9/85 .
Discussion: ahead of longwall 102 No. 1 mine subsidence zone
on date of survey. See Figure 19 .
Point No. : MC-16
Type : monitoring
Installed : 9/17-20/84 Surveyed: 8/85
Location (mine coordinate system) : 12840 .20N, 1729 . 95E
Original Elevation (ft) : 11 ,562 . 01
Total Movement Since Installation (ft) : none detected
Estimated Coal Removed Within Subsidence Zone (ft) : none
Subsidence Ratio: --
Location Relative to Mine Workings: approximate centerline,
lw 102 No. 1 mine, 1 ,313 ft ahead of face on 8/9/85 .
See Figure 19.
NOTES : Total movement is net total where both positive
and negative movements have been recorded. Projected max-
imum subsidence, where given, is theoretical maximum at a
ratio of 0.30 , assuming critical or super-critical extrac-
tion widths.