2014-02-07_REPORT - M1980244 ‎(7)‎

• Permit No: M1980244
• IBM Index Class Name: Report
• Doc Date: 2/7/2014
• Doc Name: Final Report QA Monitoring and testing volume 1 of 2 doc 1of3 Mill Site Earth works
• From: CC&V
• To: DRMS
• Email Name: TC1
• Media Type: d
• Archive: No

Cripple Creek & Victor Gold Mining Company
Mill Site Earthworks Project
Final Report
Quality uality Assurance Monitoring &Test Results
January 31, 2014
4.2.1 Underground Workings
AMEC monitored remediation of underground workings, including verification that
excavations were performed to minimum required dimensions, and that concrete
plugs, cemented rockfill, geogrid, SF, CSB, and SSF were installed as specified.
Concrete Plug and Cemented Rockfill
AMEC observed and documented testing of approximately 247 cubic yards of concrete
for slump, air entrainment, temperature, placement time, and compressive strength.
Eight tests were performed on compressive strength for a testing frequency of
approximately one test per 31 cubic yards. This exceeded the minimum specified
testing frequency of one test per every 50 cubic yards. All tests met the compressive
strength specification and the results are summarized in Appendix M.3.
Approved Cemented Rock Fill was supplied by Ute Pass Concrete. AMEC observed
the placement of cemented rockfill, including verification of all batch tickets adhering to
the approved mix design.
Geogrid and Select Structural Fill
AMEC observed Ames' installation of three layers of UX 1800 geogrid and SSF
materials. The bottom layer of geogrid was placed followed by 6 inches of SSF cover
and compacted with a Caterpillar CS563 SDVR. After compaction of the SSF material
was completed second layer of geogrid was installed transverse to the first and
another 6 -inch layer of SSF material was compacted over the second layer of geogrid;
finally a third layer of geogrid was installed transverse to the second layer followed by
a minimum of 6 inches of compacted SSF material. See IFC Drawing A45 Section 5
for a pictorial representation of the geogrid installation.
AMEC performed nine field moisture /density tests of the SSF. Proctor dry density and
optimum moisture content values for samples with greater than ten percent + 3/4 inch
material were corrected according to ASTM D4718 to facilitate direct comparison to
nuclear density values. The moisture density testing frequency of approximately one
test per 562 cubic yards exceeded the minimum specified testing frequency of one test
per 2,000 cubic yards. Nuclear density tests performed for the SSF are summarized in
Table 14. Any failing areas were re- worked, re- compacted, and re- tested until Project
Specifications were met. Any re -tests were not used to determine the testing
frequency.
4.2.2 Secondary Underdrain
AMEC verified that the underdrains were constructed as specified; UFM was placed a
minimum of 2 feet deep by 4 feet wide in the Secondary Underdrain trenches; and
oversized and unsuitable material was removed from the UFM material prior to final
placement. AMEC monitored the installation of the geotextile in the underdrains,
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