6300 MERRILL CREEK PKY BASE FILE 2018-01-01 MF Import

Quadrant JN 97092 August 13, 1997 Page 8 General Earthwork and Structural Ffll All building and pavement areas should be stripped of surface vegetation, topsoil, organic soil, and other deleterious material. The stripped or removed materials should not be mixed with any materials to be used as structural fill, but they could be used in non-structural areas, such as landscape beds. Structural fill is defined a; any fill placed under a building, behind permanent retaining or foundation wails, or in other areas where the underlying soil needs to support loads. All structural fill should be placed in horizontal lifts with a moisture content at, or near, the optimum moisture content. The optimum moisture content is that moisture content that results in the greatest compacted dry density. The moisture content of fill is very important and must be ciosely controlled during the filling and compaction process. The allowable thickness of the fill lift will depend on the material type selected, the compaction equipment used, and the number of passes made to compact the Iift. The loose lift thickness should not exceed 12 inches. We recommend testing the fill as it is placed. If the fill is not compacted to specifications, it can be recompacted before another lift is placed. This eliminates the need to remove the fill to acliieve the required compaction. The following table presents recommended reiative compactions for structural fill: Location of Minimum Ffll Placement Relative Compaction Beneath footings, slabs or � 95/o .walkways ............_..........................._._........... ..__..._...................._._......_......._...... .Behind.retainingwalls ( ..90%. ......................._.... ..................._. ..................._.. 95%for upper 12 Beneath pavements inches of subgrade; 90% below that level Where: Mlnlmum Rslalive Compacpon Is tha nGo,azpraased In percentagea,of the eompaeted dry density to tha m�zlmum dry densiry, as detertnined In accordance with ASTM Teet Desipnat�on D 1657-76(Modiflad Proetor). Use of On-Site Soil If grading activities take place during wet weather, or when the silty, on-site soil is wet, site preparation costs may be higher becau:e of delays due to rain and the potential need to import granular fill. The on-site soil is generally silty and therefore moisture-sensitive. Grading operations will be difficult during wet weather, or when the moisture content of this soil exceeds the optimum moisture content. The moisture content of the silty, on-site soil must be at, or near, the optimum moisture content, as the soil cannot be consistently compacted to the required density when the moisture content is significantly greater than optimum. The moisture content of the on-site soil was generally above the estimated optimum moisture content at the time of our explorations. The on-site, non-organic glacial till could be used as structural fill, if grading operations are conducted during hot, dry weather, when drying the wetter soil by aeration is GF.OTECti CONSULTANTS,MC.