5034 OCEAN AVE Geotech Report 2022-10-25

51xx Ocean Avenue (Parcel #00571700100100) November 1, 2017 Everett, Washington Project#17110 pounds per square foot(psf) be utilized for design purposes, including both dead and live loads. An increase of one-third may be used for short-term wind or seismic loading. However, all footings must penetrate to the prescribed bearing stratum, and no footing should be founded in or above loose, organic, or existing fill soils. Anticipated settlements of footings founded on medium dense or denser native soils or structural fill soil should be less than 1 inch. Loose or disturbed surface soils, excessive moisture present or poor foundation subgrade preparation could result in larger settlements. South Fork Geosciences should perform a foundation bearing evaluation prior to concrete placement to verify that the design bearing capacity of the soil has been attained. A foundation bearing evaluation may be required by the City of Bellevue as a condition of the building permit. Perimeter footing drains should be provided as discussed under the section titled Drainage Considerations. Lateral loads can be resisted by friction between the foundation and the supporting soils, and/or by passive earth pressure acting on the buried portions of the foundations. The spread footings must be backfilled with structural fill compacted to a dense, non-yielding condition to achieve the passive resistance provided below. The structural fill must extend horizontally outward from the embedded portion of the foundation a distance equal to at least three times the embedment depth over which the passive resistance is applied. We recommend the following design parameters. • Passive equivalent fluid = 250 pcf • Coefficient of friction =0.30 The above values are allowable and include factors of safety. Foundations—Over-excavation/Replace with Structural Fill The spread footing foundations will need to be extended through the existing fill and set to bear on native bearing soils or on new, documented structural fill soil placed and compacted atop prepared native bearing strata and properly keyed into the hill side. Excavation of the unsuitable fill soil will require laying the foundation excavation temporary cut slopes back to a stable inclination as described above to expose the medium dense to dense native sediments. The footings may be placed directly on the native sediments and a stepped foundation with tall stem walls may be placed or, once the bearing area has been properly prepared, structural fill soils may be placed, as previously described,to raise the bearing surface to the planned foundation elevations. Current structural engineering plans indicate a 2-story home that is well suited to be placed on flat ground. Based on the existing fill soils and the existing sloping ground within the proposed building footprint, it is our opinion that a home with a daylight basement is better suited for the subject property if set to bear on spread footings. SOUTH FORK GEOSCIENCES, PLLC Page 6 PO Box 1275 NORTH BEND,WA 98045 425-831-2023 I ANDREW@SFGEO.COM