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

BLAH `TINE S0. 3
ii,Rl_c GF SLl»t ti!:~blLl~;'i A::nL'i 515 Rti`iiL7b
Conditions Analyzed:
Colluvium - c = 210 psf, ~ = 16° (Residual strength)
Bedrock (other than massive sandstone) - c = 4000 psf ~ = 33° (Typical overall triaxial
shear strength performance for interbedded siltstone, sandstone, and shale)
Seepage condition - 4 ft. thick seepage zone at bedrock/colluvium interface.
X Coord. Y Coord.
Slope (f t.) (ft.) R (Et.) F SFI(°)
Section A:
E::istin~ condition:
Above portal area - S1 320 6316 161 0.614 30.48
W1 0.605 30.63
Below bench area S2 540 6246 239 0.584 32.09
W2 0.221 39.30
Future condition:
20 ft. bench with 53 320 6316 161 0.536 34.47
1:1 backslope W3 0.528 33.34
40 ft. bench with S4 358 6330 196 0.602 37.35
1:1 backslope ld4 0.521 35.86
40 ft. bench wit}
1:1 backslope-
bclc:a bunch 1a5 0.582 31.62
Section B:
Existing condition:
Above portal area S1 318 6498 328 2.141 24.32
S2 326 6488 333 2.148 24.84
wl 1.453 45.04
W2 4.925 33.47
Below bench area S3 590 6266 252 0.804 24.69
W3 0.949 23.44
Future condition:
Above portal area 54 280 6278 105 2.614 11.41
SS 328 6492 337 2.138 24.84
ld4 6.001 38.72
Below bench area S6 466 6200 120 0.780 28.24
(reclaimed) S7 590 6266 252 0.804 24.69
Section C:
Existing condition:
Above portal area S1 390 6328 182 0.741 28.29
W1 0.714 27.80
Below bench area 52 450 6220 127 0.812 25.31
W2 1.429 26.23
S3 580 6288 256 0.864 23.23
W3 0.871 23.47
W4 1.395 16.77
Future condition:
Above portal area 54 390 6328 182 0.839 25.53
WS 0.724 27.77
Below bench area SS 450 6220 127 0.778 26.11
(reclaimed) l,'6 1.321 27.45
56 580 6288 256 0.864 23.22
la7 0.868 23.36
lag 1.390 16.85