2013-09-18_PERMIT FILE - M2013064 ‎(10)‎

• Permit No: M2013064
• IBM Index Class Name: PERMIT FILE
• Doc Date: 9/18/2013
• Doc Name: New Application, Part 3
• From: Varra Companies, Inc.
• To: DRMS
• Media Type: D
• Archive: No

Geotechnical Engineering Report l�err� con
Great Western Sugar • Greeley, Colorado
January 17, 2011 . Terracon Project No 21105019
4.0 LABORATORY TEST RESULTS & ENGINEERING PROPERTIES
As requested by the client, samples were obtained from Boring No. 1 at depths of approximately
20 feet and 45 feet below existing grade, and from Boring No. 2 at a depth of approximately 25
feet below existing grade. Moisture, density, and strength testing was requested on each
sample. As shown on the grain size distribution data presented ion Exhibit B -2, we encountered
soils with significant amounts of % -inch to 2 -inch or larger diameter gravel particles at the
requested sampling depths in Boring No. 1. Typical soil strength laboratory testing including
direct shear, triaxial, or unconfined compressive strength testing is not appropriate for these
types of soils. We elected to perform soil classification testing of these soils and correlate the
soil classification information with typical soil strength parameters. We performed direct shear
testing of the sample collected from Boring No. 2. The table below summarizes our test results
as well as ranges of recommended shear strength parameters for the soils encountered.
Sample
Soil Classification
Moisture
Dry Density Internal Angle
Cohesion (psf)
I.D.
(USCS, AASHTO)
Content ( %)
(pcf) of Friction (deg)
1 e20'
GP, A -1 -a
20 -25
115 -120 - 40-45
0
1 @ 45'
SW -SM, A -1 -b
20 -25
T 115 -120 rt 32 -36'
0' -
2 @ 25
GP, A--l----a
27
118 28
731
1—Estimated
values based on soil classification, relative density, and our experience with similar soil
Direct shear testing was performed for the sample collected from Boring No 2 at a depth of
about 25 feet in general accordance with ASTM D 3080. For direct shear testing, we remolded
the sample at approximately 3 percent greater than optimum moisture content at a density of
about 95 percent of the maximum dry density as determined by ASTM D 698. Based on our
experience with similar soil types, cohesion values are typically zero (0) pounds per square foot
(psf) for gravels with less than 20 percent passing the No. 200 sieve. Additionally, the internal
angle of friction is typically between 40 and 45 degrees for medium dense gravels with less than
20 percent passing the No. 200 sieve. Therefore, we believe the direct shear test results for the
sample collected from Boring No 2 (Sample I D. 2 @ 25' shown in the table above) are not
typical for this type of material and we recommend using the ranges of soil parameters shown
for site soils presented in the table above (Sample I.D.'s 1 @ 20' and 1 @ 45').
Consideration should be given to the shear strength parameters used for design on the project.
Actual test values should be used in conjunction with published ranges of values based on soil
classifications, relative densities, and experience. We believe the shear strength parameters
listed in the table above are appropriate for the soils encountered in our borings at this site.
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