6400 MERRILL CREEK PKY 2018-01-01 MF Import

r � 11ie test pit ezcavatioac were backfilled using the relatively minimal compactive effott of � the backhce bucket. Therefore, soft spots can be racpected at these locations. We r000mmeod that thesa relatively uncompacted soils be removed from the test pits located within the pmpoaad building and pavemeat areas and the resulting excavations bacidillod with cotnpacxed strucWral � fi�►. { STRUCTURAL FILL I General . Any fill required in the proposed building and pavement areas should be placed as savdural ( fill. Tbe fill should be placed in horizontal lifts not acceading 10 inches ia laose t63ckneaa;aach lift musc be thoroughly and uniformly compacted. Fill thu will underlie footings and any fill th�t f will be 2 feet or less below the bottom of fluor slab or pavement base course devations ahmild � be compacted to at least 95 percent of the MDD (maximum dry density) as determined by the ASTM D-1557 test proceclure. Fill placed at deplhs greater than 2 fe� below these elevallons { should be compactad to at leatt 90 percent of the MDD. �ese criteria also apply W utility trench bacid'ill within building and pavement azeas. Utiliry trench backfill outside of buildtng or 1 pavement azeas should be compacted to a deasity relatively comparable to the native soil adjaeent to the trench. � All soils usad for structural fill should be free of organics, debris and other deletaious material with no individual particles larger than 4 inches maximum dimension. As the amount f of fines (that pordon passing the U.S. Standard No. 200 sieve) increases, the soil becomes I increasingty sensitive W small changes in moisture content and adequate compaction becomea � more difficult to achieve,pacticularly during wet weather. Generally, soils containing more t6en S about 5 percent fines by weight cannot be properly compacted when the moistare content is moro than a few percent from optimum. I � We recommend that a representative from our firm observe placement of suucxural fill to evaluate if procedures used and results obtained oonform with the intent of this report and the plans and specifications. A representative number of in-place density tests should be performed i Ias part of this wnstruction moniroring. r Suitability of On-site Soils l 'Ihe relatively high fines content of the till (estimated to be generally between 20 and AO percent) indicates that the on-site soil will not be suitable for use as atructural fill except 1 during periods of extended warm, dry weather. As summarized in Figure A-7, the in-situ moisture contents of the weathered till samples tested were in the range of about 25 to 32 perceat; the moisture contents of the unweathered till samples were generally in the range of about 12 to � 17 percent. The optimum moisture content of glacial till soil is typically between 8 and � l ( v c o E n y i n e e r � $ Fib No.32l6-002-R01/020.791