Laserfiche WebLink
Geotechnical Engineering Evaluation NGA File No. 1033518 <br /> Larsen Property Garage May 8,2018 <br /> Everett,Washington Summary-Page 2 <br /> be located along the toe of the moderately sloping area below an existing concrete rubble retaining wall <br /> associated with the neighboring property above and to the east of the subject property. Based on our <br /> visual observations of the concrete rubble wall it appears that the retaining wall is in disrepair,likely not <br /> engineered, and if it were to fail could potentially impact the proposed garage structure below. As a <br /> result, we recommend that the temporary excavation cuts associated with the garage construction <br /> maintain a minimum 1.5 Horizontal to 1 Vertical (1.5H:1V) gradient between the toe of the excavation <br /> and the base of the concrete rubble wall. The garage and associated excavation should be appropriately <br /> located to maintain this setback. In addition to the proposed excavation setback from the upper concrete <br /> rubble wall,we recommend that the entire eastern wall of the garage be designed as a concrete retaining <br /> wall and extend the full height of the eastern garage wall. This eastern retaining wall wouldalso be <br /> designed as a debris catchement wall to adequately protect the garage structure against potential failures <br /> on the slopes or the concrete rubble wall above. <br /> In the attached report, we have also provided general recommendations for site grading, slabs-on-grade, <br /> structural fill placement,retaining walls, erosion control, and drainage. We should be retained to review <br /> and comment on final development plans and observe the earthwork phase of construction. We also <br /> recommend that NGA be retained to provide monitoring and consultation services during construction to <br /> confirm that the conditions encountered are consistent with those indicated by the explorations,to provide <br /> recommendations for design changes should the conditions revealed during the work differ from those <br /> anticipated, and to evaluate whether or not earthwork and foundation installation activities comply with <br /> contract plans and specifications. <br /> We appreciate the opportunity to provide service to you on this project. Please contact us if you have any <br /> questions regarding this report or require further information. <br /> Sincerely, <br /> NELSON GEOTECHNICAL ASSOCIATES, INC. <br /> Khaled M. Shawish,PE <br /> Principal <br />