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

there are no important ground water aquifers discharging into
the basin.
Morphological features of the area have been very much
influenced by the harsh climate related to the exceptionally
high altitude. Erosional processes significantly contributed to
the rugged topography. Frequent avalanches continuously modify
the surface features at numerous locations along the haul roads
and at several mine benches.
2. 2 HAUL ROADS
Development of the haul road system in the Coal Basin was
a difficult task. Rugged mountainous topography, steep slopes,
severe erosion problems, potentially unstable slopes, and the
high avalanche danger comprise a set of exceptionally unfavor—
able factors for road construction. Operational requirements of
a road width of 50 to 60 feet comprise an additional factor
that increases the difficulty of the construction.
As is common in road construction in similar conditions,
the roads were mostly constructed in cuts using the sidecast
method. Fills were used mostly only as means of disposing of
material from the cut; they were not compacted or constructed
as structural fills. There is no evidence that the vegetation
or topsoil were removed from the areas of the dumped fill.
Fills built in such a manner are rarely capable of
supporting the roadway; they are usually subject to important
settlement, sloughing and erosion. Their slopes are steep,
close to the angle of repose. Their thickness is usually very
limited ("sliver fills") ; it depends on the topographic
conditions of the fill foundation. If the natural ground is
steep, the loosely dumped fill covers large areas below the
road as the material rolls down to a considerable distance
below the road. On flatter slopes , the thickness of the fill
may increase ; in such cases, the fill surface may be used for
part of the roadway. Settlements of the fill that inevitably
occur after the road construction can be rectified during the
lifetime of the road by placing additional material on the fill
surface.
Fills designed to carry parts or all the roadway were used
only exceptionally at locations where there was no road cut
(such as crossing drainages) , in sections where the cut
excavation was not feasible for operational reasons , or in
cases where the height of the cut was not acceptable for
stability reasons .
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GEO-HYDRO CONSULTING,INC.