2930 MAPLE ST KAISER PERMANENTE Geotech Report 2025-03-07

Geotechnical Engineering Report-Revised lrerracon Kaiser Everett Medical Center Everett,Washington -- ® s--------- y� December 18, 2019 Terracon Project No. 81195071 GeoReport minimum of 2 feet if the owner is willing to accept the risk of unpredictable settlements and maintenance needs. The near surface silty sand contains significant fines content (soil finer than the No. 200 mesh sieve) and is moisture sensitive. When exposed to excessive moisture and/or disturbance, the soils could become unstable with typical earthwork and construction traffic, especially after precipitation events. If possible, the grading should be performed during the warmer and drier times of the year. If grading is performed during the winter months, an increased risk for possible undercutting and replacement of unstable subgrade will persist. Additional site preparation recommendations, including subgrade improvement and fill placement, are provided in the Earthwork section. The soils which form the bearing stratum for shallow foundations are dense and are suitable for foundation loading in the natural state provided care is taken during construction to prevent disturbance of the subgrade.The Shallow Foundations section addresses support of the building bearing on native glacial till. Floor Slabs section addresses slab-on-grade support of the building. We recommend that the building or parking garage structure foundations and floor slabs not be supported on existing fill. Support of pavements on or above existing fill materials is discussed in this report. To take advantage of the cost benefit of not removing the entire amount of undocumented fill, the owner must be willing to accept the risk associated with pavements over the undocumented fills following the recommended reworking of the material. The recommendations contained in this report are based upon the results of field and laboratory testing, engineering analyses, and our current understanding of the proposed project. ASTM and Washington State Department of Transportation (WSDOT) specification codes cited herein respectively refer to the current manual published by the American Society for Testing & Materials and the current edition of the Standard Specifications for Road, Bridge, and Municipal Construction, (M41-12). The General Comments section provides an understanding of the report limitations. EARTHWORK Earthwork is anticipated to include clearing and grubbing, removal of existing pavements and buildings,general site leveling via cutting and filling, excavations, and fill placement. The following sections provide recommendations for use in the preparation of specifications for construction. Site Preparation Prior to placing fill, existing vegetation and root mat should be removed. Complete stripping of the existing pavement and fill should be performed in the proposed building and parking/driveway areas. Tree stumps and root systems should be completely removed within the building footprint. Responsive ■ Resourceful ■ Reliable 6