1310 SE EVERETT MALL WAY Geotech Report 2022-10-25

� Darden Restaurants, Inc. September 15, 2011 Proposed Olive Garden—Everett,Washington Page 3 of 12 1.4 Site Geoloqv The project site is located within the Puget Sound lowland which experienced a period of glaciations as recently as approximately 12,000 years ago. At least six events of advancing and retreating ice sheets left behind thick glacial and interglacial deposits. Review of the Preliminary Surficial Geologic Map of the Mukilteo and Everett Quadrangles, Snohomish County, Washington: State of Washington Department of Natural Resources by Smith, Mackey indicates that the site area is underlain primarily by glacial till. Glacial till is an unsorted mixture of silt, sand, and gravel that was deposited in front of an advancing glacier and was subsequently glacially overridden. Glacial till typically exhibits high strength and low permeability. 2.0 SUBSURFACE CONDITIONS 2.1 Soil Borinq Results The soil types encountered at the specific boring locations are presented on the attached Boring Logs. The stratification presented is based on a visual examination of the recovered soil samples and the interpretation of field logs by a geotechnical professional. Included on the Logs are the standard penetration resistances (SPT N-values) recorded in the individual borings at standard testing intervals to the boring termination depths. The following subsurface description is of a generalized nature and intended to highlight the major subsurface stratification features and material characteristics. The Logs presented in the Appendix should be reviewed for specific information at the individual boring locations. The Logs include soil descriptions, stratifications, penetration resistances, locations of the samples, and laboratory test data. The attached "Soil Classification Chart" illustrates the USCS classification symbols depicted on the Profile and Boring Logs included in the Appendix. The stratifications shown on the Profile and Logs represent the subsurface conditions only at the actual boring locations. Variations may occur and should be expected between boring locations. The stratifications represent the approximate boundary between subsurface materials and the actual transition may be gradual. Lines of demarcation represent the approximate boundary between subsurface materials, and the transition may be gradual. It should be noted that, although the test borings are drilled and sampled by experienced drillers, it is sometimes difficult to record changes in stratification within narrow limits, especially at great depths. In the absence of foreign substances, it is also difficult to distinguish between discolored soils and clean soil fill. 2.1.1 SurFace Approximately 2'/2 to 3'/2 inches of asphaltic concrete pavement was encountered at the ground surface in borings B-1 through B-4. 2.1.2 Fill Fill material was encountered underlying the asphaltic concrete in borings B-1, B-2, and B-4. The fill was thickest in boring B-1 where it consisted of loose to medium dense brown silty sand with some gravel and had an approximate thickness of 6 feet. Greater fill thickness may be present between the boring locations. Standard penetration test N-values ranging from 5 to 15 blows per foot indicate the relative density of the fill material in boring B-1 is loose to medium dense. The moisture content of the fill in boring B-1 ranged from about 5 to 17 percent. The fill in borings B-2 and B-4 consisted of loose to medium dense brown sand with some gravel and had an approximate thickness of 3 and 2 feet, respectively. Standard penetration test N- values ranging from 6 to 26 blows per foot indicate the relative density of the fill material in borings