2008-04-30_REPORT - M1973021 ‎(3)‎

• Permit No: M1973021
• IBM Index Class Name: REPORT
• Doc Date: 4/30/2008
• Doc Name: Geotechnical Addendum/ 2007 Annual Report
• From: Tetra Tech
• To: DRMS
• Permit Index Doc Type: Annual Reclamation Report
• Media Type: D
• Archive: No

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Discontinuity Persistence
Set 1 Set 2 Set 3 Set 4 Set 5
Very Low (6) <1 m (<3.3 ft)
Low (4) 1-3m(3.3-9.9ft) 2-8ft
Medium (2) 3 - 10 m (9.9 - 33 ft) >25 ft
High (1) 10 - 20 m (33 - 66 ft) >33 ft
Very Hi h (0) >20 m (>66 ft)
Notes: Set 3 displays changing
orientation and dip with folding,
dips generally alternate dipping
into and out of the highwall face.
Discontinuity Separation (Aperture)
Set 1 Set 2 Set 3 Set 4 Set 5
Very Tight Joints (6) <0.1 mm (< 0.003 in)
Tight Joints (5) 0.1 - 0.5 mm (0.003 - 0.02 in)
Moderately Open Joints (4) 0.5 - 2.5 mm (0.02 - 0.1 in) 0.02 - 0.1 in
Open Joints (1) 2.5 - 10 mm (0.1 - 0.4 in) 0.1 - 0.4 in 0.1 - 0.4 in
Ver Wide A erture 0 >10 mm > 0.4 in
Discontinuity Roughness
Set 1 Set 2 Set 3 Set 4 Set 5
Very Rough Surfaces (6) VR Notes:
Rough Surfaces (5) R
Slightly Rough Surfaces (3) SR SR
Smooth Surfaces (1) SM SM SM
Slickensided Surfaces (0) SL
Discontinuity Filling (Gouge)
Set 1 Set 2 Set 3 Set 4 Set 5
e clay, staining, shear, etc none (6) none (6) clay (2)
:kness up to 0.02 in
mated Compressive Strength -
page none, moist, drippin etc none none none
Discontinuity Wall Face Weathering
Set 1 Set 2 Set 3 Set 4 Set 5
Unweathered (6) UW
Slightly Weathered (5) SW
Moderately Weathered (3) MW MW
Highly Weathered (1) HW HW HW
Completely Weathered (0) CW
Residual Soil 0 RS
RMR Classification: Poor to Fair Rock (38 - 55)
Additional Notes: Biotite Gneiss. Rock displays moderate strength as well as some massive zones (thickness up to 14 inches with no
discontinuities). The weathered zone increases in thickness towards the top of the highwall due to the proximity to the
ground surface. Prior to mining, rock in area was part of a resistant ridge of material.