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W.W. Wheeler & Associates, Inc. <br /> November 27, 1995 <br /> Page 2 <br /> rocks were. probably pushed out of the Zone 1 into Zone 2 during <br /> construction. The finer matrix appears to be the same in both <br /> zones. <br /> All of the material excavated <br /> e breach may be replaced <br /> should be pushed out of <br /> in the breach. Rocks greater than 6 inches <br /> the Zone 1 area shown on the project drawings. <br /> Com action of Breach Backfill Embankment: Specifications require <br /> the fill be compacted to a minimum of 98% standard Proctor maximum <br /> dry density within 2 percentage points of the optimum moisture <br /> content. The two samples which were obtained from the breach <br /> excavation were also tested in our laboratory to determine the <br /> moisture-density relationships. The "Zone 1" sample had a maximum <br /> dry density of 131. 6 pcf and optimum moisture content of 8 . 1% . The <br /> "Zone 2" sample possessed a maximum dry density of 130.0 pcf at <br /> 9. 0%. <br /> Records of Zone 1 material placed in 1968 during Stage 2 <br /> completion of Dam 4 , between elevations .of 10,712 and 10,722 feet <br /> showed three different moisture-density relationships. Maximum dry <br /> densities ranged from 129. 2 to 131.9 pcf. Optimum moisture <br /> contents ranged from 8.9 to 9.6 percent. <br /> Based on these values and the recent laboratory tests results, <br /> we recommend a maximum dry density of 131 pcf and optimum moisture <br /> content of 9 percent be used for field compaction test evaluation. <br /> At 98 percent compaction, a minimum field density (dry) of 128 pcf <br /> and a moisture content between 7 and 11 percent will be required. <br /> Based on the apparent uniformity of these soils, this value should <br /> be practical for all of the fill. However, if upon failure and re <br /> compacting fill with diligent effort, this density cannot be <br /> obtained, such fill should be sampled and moisture-density <br /> relationship testing performed on that specific material. <br /> If there are any questions regarding this information, please <br /> call. <br /> Sincerely, <br /> KUMAR & ASSOCIATES, INC. <br /> By <br /> M us J. Pardi, P. E. <br /> MJP/ck <br /> cc: file, book <br /> Kumar & Associates, hic. <br />