REP25496

• Permit No: C1981033
• IBM Index Class Name: Report
• Doc Date: 3/23/1992
• Doc Name: SUBSIDENCE SLOPE STABILITY MONITORING BEAR COAL CO BEAR MINE 3 SOMERSET CO
• From: UTE ENGINEERING SURVEYING CO
• To: MLR
• Permit Index Doc Type: SUBSIDENCE REPORT
• Media Type: D
• Archive: No

- Mined Land Reclamation 12 March 17, 1992
The change in horizontal position can be attributed to a variety
of factors (1) the error of closure and adjustment inherent in
any survey; (2) using new field surveying equipment; (3) actual
movement of the monuments due to subsidence. The error of
closure for the July, 1990 traverse was 0.35 feet of error in a
total traverse distance of 18,207 feet which reflects a closure
ratio of 1 part in 52,000.
The elevations show a change that reflects an increase in value
of 0.04 feet on the average. Elevations are obtained by
trigonometry.
The closures of our elevations using trigonometric leveling have
been very good. Errors ranging from 0.10 feet to no error.
TABLE 4-SLOPE STABILITY
RELATIVE MOVEMENT
NOVEMBER, 1990 TO JULY, 1991
Point Horizontal Distance Bearing Elevation
No.
U16 0.15 N15o57'E -0.02
U17 0.11 N15°15'E +0.04
U18 0.11 N21°48'E +0.03
U19 0.07 N26°34'E No Change
U23 0.08 S82o52'E +0.03
TABLES-SUBSIDENCE
SUBSIDENCE POINT CHANGES - RELATIVE MOVEMENT
JULY, 1991 TO NOVEMBER, 1991
Point Horizontal Distance Bearing Elevation
No.
UT2 0.27 NBO°51'E -0.14
U4 0.19 S65o28'E -0.20
U1 0.19 S47°34'E -0.09
U3 0.10 503°26'E -0.11
U2 0.14 526°40'E -0.12
U5 0.16 S39°56'W -0.17
U9 0.15 S25°45'E -0.07
UA1 0.09 S51o20'W -0.06
U8 0.09 S07°49'W -0.09
The change in horizontal position can be attributed to a variety
of factors (1) the error of closure and adjustment inherent in
any survey; (2) using new field surveying equipment; (3) actual
movement of the monuments due to subsidence. The error of
closure for the November, 1991 traverse was 0.09 feet of error in
a total traverse distance of 18,207 feet which reflects a closure
ratio of 1 part in 202,300.