Laserfiche WebLink
conditions. and then mechanically compacted in place to a minimum relative compaction of 90 <br />percent. A representative of the project geotechnical consultant should probe and test the <br />backfills to verify adequate compaction. <br />As an alternative for shallow trenches where pipe or utility lines may be damaged by <br />mechanical compaction equipment. such as under building floor slabs, imported clean sand <br />exhibiting a sand equivalent (SE) value of 30 or greater may be utilized. The sand backfill <br />materials should be watered to achieve near optimum moisture conditions and then tamped into <br />place. No specific relative compaction will be required: however. observation. probing, and if <br />deemed necessary, testing should be performed by a represenlative of the project geotechnical <br />consultant to verify an adequate degree of compaction and that the backfill will not be subject <br />to settlement. <br />Where utility trenches enter the footprint of the buildings. they should be backfilled through <br />their entire depths with on-site fill materials. sand-cement slurry. or concrete rather than with <br />any sand or gravel shading. This "Plug" of less- or non-permeable materials will mitigate the <br />potential for water to migrate through the backfilled trenches from outside of the buildings to <br />the areas beneath the foundations and floor slabs. <br />8-ft:--Dennis- l -01