5402 25TH AVE W 2016-01-01 MF Import

. • City of Everett � - . c/o Ron and Kelly Krueger • August 22, 2007 , Page 2 City of Everett has indicated a need for geotechnical assessment and clarification regarding excavation criteria and proximity to the southern drainage slope feature. EVALUATION: In order to augment the existing site geotechnical information, 2 soil test holes were hand dug by this engineer on Hugust 20, 2007 (see Site Plan for locations). Both test holes revealed similar sub-grade conditions, namely: 0" to 6" Lawn, organics, roots, and organic silt (moist due to recent rains) 6" to 16" Moderately dense sand;� loam (moist) grading to slightly sandy silt 16" to 38" (bottom of test holes) Very dense weatheied glacial Till No water was e.^,countered in either of the 2 test holes. Both test hole walls remained vertical and stable. No sloughing or caving occurred. CONCLUSIONS ! RECOMMENDATIONS: Based on ttie findings of this investigation, and experience with similar sites in the area, the Krueger property at 5402 25�h Ave. W, Everett, Washington is aeotechnicallv approved for the proposed house addftion and lower wine cellar, subject to the following: . Excavation adjacent the existing foundation must wmply with attached recommendations and on-site inspections. Note that two options are provided for the lower level wine cellar: setback distance of a minimum of 3.0 feet, or pin-pile stabilization of exi�ting foundation and adjacent soil cuts (see design sketches). . Standard reinforced continuous and spread footings. Allowable bearing pressure: 3,000 p.s.f. . Equivalent fluid pressure of 35 p.c.f. is recommended for a.:y retaining wall design provided drainage zone is inspected and ver'fiied by this engineer. . For retaining wall design, use friction factor of 0.55 and passive pressure of 350 p.c.f. I, . Geotechnical inspections by this engineer ri�or to any faundation concrete placement. \ "�