1505 112TH ST SW 2018-01-02 MF Import

GE07TCBMCAL ENGDIEEPING STUDY Wells Development Corporation E-3813 July 27, 1992 Page 4 The building and pavement areas should tic stripped and cleared of all structures, foundations, slabs, trees, existing utilities lines, surface vegetation, all organic [natter and any other deleterious material. There is the possibility of some contaminated materials on the site. The site should be clear of all contamination prior to the start of grading operations. Stripped materials should not be trued with any materials to be used as structural fill. Excavations resulting from the demolition and removal of any existing buildings and/or other associated subteraneart structures (i.e., seepage pit, dry well, etc.) should be c: cared of all debris and loose/disturbed soil prior to backfilling with suitable compacted materials. Following stripping and overexcavation operations, the ground surface where structural fell, foundations, asphalt pavements or slabs are to br. placed should be proofrolied. All proofroiling should be performed under the observation of a representative from this office. Soil in any loose or soft areas, if recompacted and still yielding, should be overexcavated and replaced with structural fill to a depth that will provide a stable base beneath the general structural fill. The optional use of a geotextile fabric placed directly on the overexavated surface may help to bridge unstable areas when encountered. The basement slabs of the existing residences may be left in place; however, the slabs and foundation must be broken into pieces of maximum diameter of eight inches. The voids in the concrete rubble should be filled with sand prior to the start of backfilling operations. Structural fill should then be phud in accordance with the recommendations in this section. The fill materials should be placed at or near the optimum moisture content. Fill under pavements and walks should also be placed in horizontal lifts and compacted to 90 percent of maximum density except for the top twelve (12) inches which should be compacted to 95 percent of maximum density (ASTM D- 1557-78). On -site soils may be used as structural fell; however, at the time of our exploration, they were generally above the optimum moisture content and may need to be aerated before use as structural fill, provided the grading operations are conducted during dry weather. Since the on -site soils have it significant amount of fines and are moisture -sensitive, compaction and grading will be difficult if the soil moisture remains above the optimum moisture content. If necessary, the moisture content can be reduced by aeration in dry weather, or by intermixing lime or cement to ab'x)rb excess moisture.ln any case, structural fill which is to be placed in wet weather should consist of a granular material with a maximum size of three inches and no more than five percent fines passing the No. 200 sieve based on the minus 3/4-inch fraction. During dry weather, most compartible non -organic soil can be used as structural fill. it is recommended that any structural fill planned for use on the site be submitted for approval prior to import. Earth Consultants. Inc.