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Aug. 31. 2004 3:47PM CHARLES MORGAN & ASSOC. No. 0044 P. 9 <br /> - s Grandview Homes, LLC JN 99040 <br /> February 16.1999 Page 7 <br /> The allowable thickness of the fill lift will depend on the material type selected, the compaction <br /> equipment used, and the number of passes made to compact the lift. The loose lift thickness <br /> should not exceed 12 inches. We recommend testing the fill as it is placed. If the fill is not <br /> compacted to specifications, it can be recompacted before another lift is placed. This eliminates <br /> the need to remove the fill to achieve the required compaction. The following table presents <br /> recommended relative compactions for structural fill: <br /> Beneath footings, slabs 95% <br /> or walkways <br /> Behind retaining walls 90% <br /> 95%for upper 12 inches of <br /> Beneath pavements subgrade; 90%below that <br /> level <br /> Where;Minimum Relative Compaction is the ratio,expressed In <br /> percentages,of they compacted dry density to the Maximum dry <br /> density, as determined in accordance with ASTM Test <br /> Designation D 1557-78(Modified Proctor). <br /> Use of On-Site Soil <br /> If grading activities take place during wet weather, or when the silty, on-site soil is wet, site <br /> preparation costs may be higher because of delays due to rain and the potential need to <br /> import granular fill. The on-site soil is generally silty and therefore moisture-sensitive. <br /> Grading operations will be difficult during wet weather, or when the moisture content of this <br /> soil exceeds the optimum moisture content. <br /> The moisture content of the silty, on-site soil must be at, or near, the optimum moisture <br /> content, as the soil cannot be consistently compacted to the required density when the <br /> moisture content is significantly greater than optimum. The moisture content of the on-site <br /> soil was generally above the estimated optimum moisture content at the time of our <br /> explorations. The on-site glacial till underlying the topsoil could be used as structural fill, if <br /> grading operations are conducted during hot, dry weather, when drying the wetter soil by <br /> aeration is possible. During excessively dry weather, however, it may be necessary to add <br /> water to achieve the optimum moisture content. <br /> Moisture-sensitive soil may also be susceptible to excessive softening and "pumping" from <br /> construction equipment, or even foot traffic, when the moisture content is greater than the <br /> optimum moisture content. It may be beneficial to protect subgrades with a layer of <br /> imported sand or crushed rock to limit disturbance from traffic. <br /> • Structural fill that will be placed in wet weather should consist of a coarse, granular soil with'a silt or <br /> clay content of no more than 5 percent. The percentage of particles passing the No. 200 sieve <br /> should be measured from that portion of soil passing the three-quarter-inch sieve. <br /> LIMITATIONS <br /> The analyses, conclusions, and recommendations contained in this report are based on site <br /> conditions as they existed at the time of our exploration and assume that the soil and groundwater <br /> / s <br /> GEOTECH CONSULTANTS,INC, (, �/ <br />