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Veritas Construction Inc ES-4011.03 <br /> June 17, 2016 Page 10 <br /> Revised June 22, 2016 <br /> Foundations <br /> In our opinion, the proposed development may be constructed on conventional continuous and <br /> spread footing foundations bearing upon competent native soil, recompacted native soil, or new <br /> structural fill. Where loose or unsuitable soils are exposed at subgrade elevations, the soil <br /> should be compacted to structural fill specifications or overexcavated further as recommended <br /> by the geotechnical engineer and replaced with a suitable granular structural fill material. <br /> Assuming the foundations are supported as described in this report, the following parameters <br /> should be used for design: <br /> • Allowable soil bearing capacity 3,000 psf* <br /> • Coefficient of base friction 0.40 <br /> • Passive resistance 300 pcf (equivalent fluid)** <br /> * ESNW can reevaluate the recommended allowable soil bearing capacity if heavy column loading <br /> (associated with post-tensioned slab construction) is anticipated. <br /> **Assumes foundations backfilled with structural fill or poured neat against competent soils. <br /> For short term wind and seismic loading, a one-third increase in the allowable soil bearing <br /> capacity can be assumed. A factor-of-safety of 1.5 has been applied to the friction and passive <br /> resistance values. <br /> With structural loading as expected, total static settlement in the range of one inch is <br /> anticipated, with differential settlement of about one-half inch or less over a typical column bay <br /> spacing. The majority of the static settlements should occur during construction, as dead loads <br /> are applied. <br /> Slab-On-Grade Floors <br /> Slab-on-grade floors for the proposed residential structures should be supported on a well- <br /> compacted, firm and unyielding subgrade. Unstable or yielding areas of the subgrade should <br /> be recompacted or overexcavated and replaced with suitable structural fill prior to construction <br /> of the slab. A capillary break consisting of a minimum of four inches of free draining crushed <br /> rock or gravel should be placed below the slab. The free draining material should have a fines <br /> content of 5 percent or less (percent passing the #200 sieve, based on the minus three-quarter <br /> inch fraction). In areas where slab moisture is undesirable, installation of a vapor barrier below <br /> the slab should be considered. If a vapor barrier is to be utilized it should be a material <br /> specifically designed for the use as a vapor barrier and should be installed in accordance with <br /> the manufacturer's specifications. <br /> Earth Solutions NW,LLC <br />