8.3 SR 04-04-2022 - Laserfiche WebLink

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March 2, 2020 Project 19-460 Jackson Hills Residential Suite Phases II- IV Elk River, Minnesota wet or frozen soils, highly expansive soils, rubble, debris and rocks in excess of 6 inches in diameter. The fill should be as uniform as possible both in composition and moisture content. We recommend all fill be compacted in 8-inch loose lifts to the minimum relative density levels shown in the table below: Location Recommended Compaction Level (percent of Std. Proctor ASTM D698) Below Foundations and Building Slabs, including oversizing areas during soil correction 100% Interior wall backfill during building construction 98% Exterior Wall backfill during building construction 95% Below Pavements, deeper than 3 feet from finished subgmde 95% Below Pavements within 3 feet of finished subgrade 100% Landscape Areas 90% All fill should be compacted at a moisture content within plus or minus 2% of the optimum moisture as determined by a standard proctor. We recommend compaction tests be taken on any fill in the building areas at a rate of one test per vertical foot per 2,500 square foot area, with a minimum of two tests per fill area. We recommend compaction tests be taken on the foundation wall backfill at a rate of one test per 2 vertical feet per 200 linear feet of wall backfill. Foundations: We assume the foundations will bear on compacted imported granular fill material. The N-values recorded in the penetration borings indicate that the majority of the existing native sand soils on this site are in a loose condition susceptible to settlement. De -watering the site and compaction of the backfill to 100% will help to limit settlement to within tolerable limits for a wood framed building. All exterior footings should be placed at a minimum depth of 42 inches below proposed final grade to provide protection from frost damage. Interior footings in heated areas can be placed at any convenient depth as long as they are on properly compacted fill. Page 7