7000 HARDESON RD 2018-01-02 MF Import

disclosed by scarification and prerolling should be excavated as necessary and backfilled with 'structural fill' as discussed subsequently. 4.2 Structure! Fill All fill material should be placed in accordance with the following recommendations for 'structural fill'. Prior to structural fill placement, the surfaces to receive structural fill should be prepared as previously described. All structural fill should be free of organic material, debris and other deleterious materials. The maximum individual particle size of soils used for fill should be less than 6-inches in diameter. Structural fill should be placed in horizontal lifts no greater than 8-inches in loose thickness and each lift should be uniformly compacted to at least 95 percent of the modified Proctor maximum dry density (ASTM:D 1557). The upper foot of subgrade soils in cut areas under pavements should be, compacted to at least 95 percent (ASTM:D 1557). as noted in the site preparation section of this report. We recommend that a representative of AEE be present during grading so that an appropriate number of density tests may be conducted as structural fill placement occurs. In this way, the adequacy of earthwork may be evaluated as it proceeds. Laboratory sieve analysis results presented in Appendix B of this report indicate that near - surface soils typically contain approximately 20 percent fine-grained soils (silt and clay) and are at or near their optimum moisture content. During and immediately after the wet season, these Soils likely are likely to be wetter than optimum. Typically, the optimum moisture content for glacial till soils is between 9 and 13 percent. Selective drying may include windrowing surficial materials during extended periods of dry weather. Soils which are dry of optimum may require water to be added by the use of water trucks to increase the moisture content prior to compaction. In the event that inclement weather or wet site conditions preclude the use of on -site $ots or non -select materials as structural fill, we recommend that select, free -draining granular material be used. Free -draining fill should also be used for all backfill within 2 feet of any external basement and retaining walls. If import fill is required in wet site or weather conditions, such materials should generally contain less than 5 percent passing the U.S. No. 200 Sieve based on that soil fractin.i passing the U.S. No. 4 Sieve, and should not contain discrete particles greater than 6-inches in diameter. 4.3 Foundation Considerations The proposed structures may be supported on conventional spread and continuous footings with slab -on -grade floor support. As discussed in the following report section, preloading and surcharging are recommended in a portion of the site prior to construction of the foundations and floor slab. Footings may be constructed on either undisturbed near surface medium dense to very dense silty sand or within structural fill compacted to at least 95 percent of the modified Proctor maximum dry density (ASTM:D 1557) placed above properly prepared