REP06340

• Permit No: C1981033
• IBM Index Class Name: Report
• Doc Date: 4/22/1982
• Doc Name: 1982 STABILITY ANALYSIS OF PORTAL & ACCESS ROAD AREAS
• From: ROCKY MOUNTAIN GEOTECHNICAL
• Permit Index Doc Type: SUBSIDENCE REPORT
• Media Type: D
• Archive: No

1
SLOPE ST:IBILITY SUhit44R`i SriEET
BEAR I•fINE N0. 3
Conditions Analyzed:
Colluvium - c = 360 psf, 0 = 23° (Peak strength)
Bedrock (other t}~an massive sandstone) - c = 4000 psf, ¢ = 33° (Typical overall triaxiai
shear strength performance for interbedded siltstone, sandstone, and shale)
Seepage condition - 4 ft. th ick seepage zone at bedrock/co lluvium interface.

l t•farginally Minimum Critical Mo de
J Slope Stable Stable Unstable F.S. Circular P lane

Section A:
Existing condition:
i Above portal area X 0.933 X
Below bench area X 0.803 X
I
I Future condition:
~
~ 20 ft. bench - above portal X 0.816 X
40 ft. bench - above portal X 0.826 X
1 i 40 ft. bench - below bench X 0.895 X
Section B:
1 Existing condition:
Above portal area X 2.141 X
Below bench area X 1.240 X
- Future condition:
I Ai~ove portal area X 2.089 X
Below bench area (reclaimed) X 1.240 X
Section C:
Existing condition:
Above portal area X 1.132 X
Below bench area X 1.264 X
Future condition:
Above portal area X 1.145 X
Below bench area (reclaimed) X 1.210 X
Section D:
Existing condition:
Above portal area X 1.237 X
Below bench area X 1.255 X
Future condition:
' Above portal area X 1.280 X
Below bench area (reclaimed) X 1.243 X
Section E:
t Existing condition:
Above haul road X 1.257 X
Below haul road X 1.235 X
Future condition:
Above haul road X 1.198 X
Below haul road X 1.182 X
'
1