2011-08-26_REPORT - M1980244 (28)

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ameO 4.1.5 Permeability Tests AMEC conducted permeability tests of SLF. AMEC conducted fifty -seven (57) permeability tests of re- compacted samples of SLF. The testing frequency (approximately one test per 903 cubic yards) exceeded the minimum specified testing frequency of one test per 4,000 cubic yards. Testing was performed with a flexible -wall permeameter, during material processing, with back - pressure saturation and a constant rate of flow (ASTM D5084, Method D). The fill was re- compacted to 95 percent of the standard Proctor (ASTM D698- 07) maximum dry density at the optimum moisture content (as determined from oven -dried samples). Laboratory tests yielded coefficients of permeability for the CQA samples from 8.9 x 10 -7 cm /sec to 2.9 x 10 -9 cm /sec, all of which are less than the specified maximum permeability of 1 x 10-6 cm /sec. The permeability test results for the SLF met project specifications and are presented in Appendix H -3 and summarized in Table 7. 4.2 Field Testing and Monitoring AMEC observed all fill operations in the 2011 Phase 5 VLF OSA 2nd Portion to verify, when necessary, lift thickness, adequate compaction, and acceptable moisture conditions. Holes made in the fill during testing were backfilled and tamped with fine bentonite materials. AMEC standardized nuclear gauges at the start of each day's work according to ASTM D2922. 4.2.1 Subgrade Preparation AMEC monitored subgrade preparation, including verification that Ames compacted the subgrade with a smooth drum vibratory roller (SDVR) compactor. AMEC verified that Ames removed protruding rocks from the subgrade surface prior to SLF placement. AMEC verified that the subgrade surface was moisture conditioned, smooth, and unyielding prior to SLF placement. AMEC Earth & Environmental, Inc. 2000 S Colorado Blvd 2 -1000 Denver, CO 80222 Tel 303 - 935 -6505 Fax 303 - 935 -6575 www.amec com 20