4935 GLENWOOD AVE 2016-01-01 MF Import

' Jordan Construction July 25, 2000 JN 00284 Page 8 Structural fill is defined as any fill placed under a building, behind permanent retaining or foundation walls, or in other areas where the underlying s�il needs to support loads. All structurai 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 closely 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 lift. The loose lik 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 achieve the required compaction. The following table presents recommended relative compactions for structural fill: Beneath footings, slabs 95% or walkways Behind retainin walls gpo�o Beneath avements 95��0 for upper�12 inches of P subgrade; 90/o below that level Where;Minimum Relative Compactlon is the ratlo, expreasad in percentages, of the compaeted dry denalty to the maxlmum dry density, as Aetermined In accordance with ASTM Tast Desfgnation D 1557-91(Modifled Proctor�. 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 because of delays due to rain and the potential need to import granular fill. The on-site weathered and fill soils are generally silty and therefore moisture sensitive. Grading operations will be di�cuit 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 near the estimated optimum moisture content at the time of our explorations. The on-site filis soils underlying the topsoil should not be used as structural fill under the footings, however may be able to be used under the concrete slab if grading operations are conducted during hot, dry weather, when drying the wetter soil by aeration is possible. During excessively dry weather, however, it may be necessary to add water to achieve the optimum moisture content. Moisture-sensitive soil may also be susceptible to excessive sokening and "pumping" from construction equipment, or even foot traffic, when the moisture content is greater than the optimum moisture content. It may be beneficial to protect subgrades with a layer of imported sand or crushed rock to limit disturbance from tra�c. GEOTECH CONSULTANTS, INC. /(,�j