1920 MERRILL CREEK PKY 2018-01-01 MF Import

I SHANNON�WILSON.INC. disposed of off-site or stocl�iled for landscape amas and only the native glacial soils used � for fill. In addition, if outwash is encountered during excavafion it should be stored for use in wet weather ceriods or in the event the till-like soils are too wet to be compacted. � As mentioned above, even the glacial, till-like soils may be difficult to work with because of the high moisture content. If such a condition exists, depending on the weather 1 during grading and schedule, the use of admixtures may be beneficial. We estimate that I treatment with lime would inv�olve the addi6on of 2 to 6 percent of lime to the wet soil (by weight). Lime wouid absorb excess moisture, reduce plasdcity, and improve worlmbility of the wet soil. It wvuld be cheaper than cement stabili7ation but would not be effecflve during 1 wet weather. Lime stabiliration was used in the recently completed Washington Natural Gas facility, near the proposed project site. The cost for soil-lime stabilizadon ranged from 51.50 to $2.50 per cubic yard (cy), as compared to the export of on-site soils and import of � clean, pit-run sand and gravel at $18/cy. We esGmate that cement stabilization would Iinv�olve the addi6on of 2 w 4 percent of cement to the wet soil (by weight). Cement also would absorb excess moisture, improve worlcability, and increase the strength of the wet I soil. T'he increase in strength could lead to reducing base coarse thicknesses for parldng and drive areas and thus reduce project costs. Cement stabili7ation is effective during wet weathec For planning purposes only, the costs of stabilizing sc�il with cement could be on � the order of$6 to $7/cy. If the� is not enough suitable on-site material available for the necessary fill application, imported structural 811 matcrial will be required. Imported structucal fill should I consist of mzsonably well-gradei sand or sand and gravel, free of otganics and other deleterious materials, with a maaimum particle size of 3 inches. It should contain not moce I than 30 pem.ent fines (material passing the No. 200 sieve), by wcight, based on wet-sieving the soils frdction passing the 3/4-inch sieve. Imported sWctural fill should be at a moistu�e content near the optimum value to allaw proper compacdon. � In wet weather or under wet condidons, it wili be necessary to impert an all-weather ISll material for use as structural fill or try mixing addidves to the soil, as discussed previously. An all-weather flll should consist of masonably w�ll-graded sand or sand and � gravel, free of organics and other deleterious materials, with a maximum particle size of 3 inches. It should contain not mo�e than 5 percent fines (material passing the No. 200 sieve), I � W-6693-01 20