4933 GLENWOOD AVE 2016-01-01 MF Import

Jordan Construction ' JN 00284 July 25, 2000 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 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 thc greatest compacted dry density. The moisture content of fill is very important and must be closely controiled 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 lift thickness shou J not exceed 12 inches. We recommend testing the fiii as it is piaced. If the fill �s 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 compacti�� The following tsble presents recommended relative compactions for structural fill: Beneath footings, slabs 95% or walkways Behind retaining walls 90"/0 95% tor uppe: 12 inches of Beneath pavements subgrade; 90% below that levei Whero: Mlnimum Rclative Co�npactlon is the ralio, expressed in percentages, of the compacted dry density lo lhe maxlmum dry density, as determined In accordance with ASTM Test Designatlon D 7557-91 (�dodified 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 soiis are generally silty and therefore moisture sensitive. Grading operaticns will be difficult during wet weather, or when the inoisture 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 fills soils underlying the topsoil should not be used as struclural fill under the footings, however may be abie 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 softening 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 traffic. r � � � �, GEOTECH CONSULT/:NTS, INC.