1987-12-01_PERMIT FILE - C1981017 ‎(289)‎

• Permit No: C1981017
• IBM Index Class Name: PERMIT FILE
• Doc Date: 12/1/1987
• Doc Name: Geotechnical Investigations Mine Portal Benches and Haul Roads
• Section_Exhibit Name: Chapter V Appendix V-E-II
• Media Type: D
• Archive: No

occasionally interfere with road use. Instability of fills is
generally confined to minor to moderate erosion and rilling,
with minor sloughing. Important instability is mostly severe
gullying 'due to erosion. At approximate road station 72+50,
erosion of the fill has resulted in steep sloughing ,
undercutting the edge of the road.
Road D (see Table 6) from the junction of B- and C-roads
to No. 1 mine bench has a total length of 12, 000 feet, with an
average grade of 8.7%. Almost the entire road is in cut and
fill configuration, with the remainder in fill only. Cuts are
predominantly in rock or mixed soil and rock, with few in soil.
only. Most cuts range up to 40 feet in height, but none exceeds
40 feet. Cut slopes are all generally steep, with many exceed-
ing an angle of 600. The height of the fill generally exceeds
20 feet_ and ranges up to greater than 40 feet. All fill slopes
appear to be constructed at a 30 - 450 angle of repose.
Only minor stability problems occur in the majority of
cuts. Occasional moderate stability problems consist mostly of
moderate sloughing and undercutting of the crest of the cut.
Important stability problems are rare , isolated sloughs of
relatively large size. Fill slopes are predominantly stable
with only minor erosion and sloughing. Occasional moderate
instability is noted where moderate erosion and gullying have
occurred , usually at stream crossings. A few important
stability problems occur as small isolated areas of sloughs,
slumps or severe erosion gullies.
Road D-A (see Table 7) is a very short road to No. 2 mine
bench from the D-road , 600 feet long at a grade of 9. 2%. Half
of the road is in cut and fill construction, and the other half
is in cut only. Cuts are either in rock or mixed soils and
rock. Heights of cuts range up to a maximum of 40 feet, and
none are less than 20 feet high. Angles of cuts are steep,
often exceeding 600. Fills are low, and range up to 40 feet in
height. All fill slopes stand 30 - 450, the approximate angle
of repose.
No cuts or fills have any significant stability problems.
The rock cuts are subject to minor rockfall and sloughing .
Road E (see Table 8) from the junction of A- and B-roads
to the junction of F- and G-roads has a length of 6, 250 feet ,
and an average grade of 8. 5%. Most of the E-road is in cut and
fill configuration. Road cuts are distributed between soil and
rock. Most cuts are less then 40 feet in height , but
occasionally range up to 60 feet high. Cut slopes are steep,
with many cuts steeper than 600. Fills are generally less than
40 feet in height, but exceed 40 feet in a few locations.
Again, all fills are constructed at the approximate angle of
• repose (30 - 450) .
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GEdHYDRO CONSULTING,INC.
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