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

• SECTION 3 - HIGH ,THICK FILL, ROAD
GENERAL: A typical road fill constructed where excessive quantities
of material were available or where topographic
conditions did not allow construction of the road in a
cut. The fill was probably built using side-cast method.
It was not compacted. Slopes of fill are close to the
angle of repose. It has to be expected that foundations of
the fill were not prepared ; vegetation was not removed ,
topsoil was not stored. On steep slopes, fill was not
keyed into the foundation.
STABILITY AND OTHER PROBLEMS: Stability of the fills is marginal ;
it can be assumed that factors of safety are close to
unity. For any analytical considerations, F.S. = 1. 1
should be considered for current conditions. Incipient
stability problems may be indicated by tension cracks
close to the fill crest. Occurrence of ground water may
seriously influence the stability of the fill . Erosion ,
gullying , Tilling and sloughing of the fill surface are
common.
RECLAMATION CONCEPT: Flatten the fill surface to a slope of 1.5
1 or flatter. Prevent erosion, gullying and rilling by
careful surface drainage. Vegetate.
METHOD OF RECLAMATION: Construct a pioneer road to the toe of the
fill , if not accessible. Road necessary for dozer and
backhoe only. At the design toe of flattened fill , remove
vegetation and topsoil from area of future fill expansion.
Store topsoil. Whenever the side slope of natural ground
exceeds 3 : 1 (33 percent) , the existing ground will be
stepped so that the fill can be keyed into it. The keyway
shall be a minimum 10 feet in width and it shall begin at
the design toe of the reconstructed fill. Natural ground
flatter than 3 : 1 shall be scarified. Material from the
upper part of fill will be pushed down the slope of the
fill to the projected toe. Any organic material , coal ,
frozen material will be disposed of. The material will be
spread out in lifts not exceeding 12 inches in thickness.
Each lift (layer) will be completed , levelled and com-
pacted evenly by routing the hauling and levelling equip-
ment over the entire width of the embankment. Erosion
control measures will be taken to eliminate the possi -
bility of surface erosion, gullying and rilling. The crest
of the reconstructed fill shall be rounded and shaped to
eliminate sharp changes of the slope. Vegetation cover
will be established on the surface of the reconstructed
• fill .