Laserfiche WebLink
GeoTest Services, Inc. <br />2405 Hillside Lane, Everett, WA <br />October 8, 2021 <br />Project No. 21-0845 <br />properly compacted structural fill placed directly over these soils. GeoTest recommends that <br />qualified geotechnical personnel confirm that suitable bearing conditions have been reached <br />prior to placement of structural fill or foundation formwork. <br />To provide proper support, GeoTest recommends that existing topsoil, existing fill (if present), <br />and/or loose upper portions of the native soil be removed from beneath the building foundation <br />areas. Dense, native soils are unlikely to require much preparation. However, if footings or <br />structural fill will be placed atop previously placed fill or native Transitional Beds at depth, the <br />surface should be compacted to a firm and unyielding condition with a smooth -drum roller, hoe - <br />pack, or a similar piece of construction equipment. Once suitable bearing conditions have been <br />confirmed, then foundations can bear directly on native soils or on properly compacted structural <br />fill as described in the Fill and Compaction section of this report. <br />Continuous and isolated spread footings should be founded 18 inches, minimum, below the <br />lowest adjacent final grade for freeze/thaw protection. The footings should be sized in <br />accordance with the structural engineer's prescribed design criteria and seismic considerations. <br />Allowable Bearing Capacity <br />Assuming the above foundation support criteria are satisfied, continuous or isolated spread <br />footings founded directly on remedially compacted, firm and unyielding, native Transitional Beds <br />or on compacted structural fill placed directly above these soils may be proportioned using a net <br />allowable soil bearing pressure of 2,000 pounds per square foot (psf). <br />The 'net allowable bearing pressure' refers to the pressure that can be imposed on the soil at <br />foundation level. This pressure includes all dead loads, live loads, the weight of the footing, and <br />any backfill placed above the footing. The net allowable bearing pressure may be increased by <br />one-third for transient wind or seismic loads. <br />Foundation Settlement <br />Settlement of shallow foundations depends on foundation size and bearing pressure, as well as <br />the strength and compressibility characteristics of the underlying soil. If construction is <br />accomplished as recommended and at the maximum allowable soil bearing pressure, GeoTest <br />estimates the total settlement of building foundations to be less than one inch. Differential <br />settlement between two adjacent load -bearing components supported on competent soil is <br />estimated to be less than one half the total settlement. <br />Floor Support <br />Floor slabs for the proposed construction can be supported on remedially compacted, firm and <br />unyielding, native subgrade (Transitional Beds), or on properly placed and compacted structural <br />12 <br />