330 ELM ST VIEW RIDGE ESTATES 2022-04-04

Geotechnical Engineering Evaluation NGA File No. 1085419 View Ridge Estates 330 Building Settlement March 22,2019 Everett,Washington Page 2 SITE CONDITIONS Surface Conditions The site consists of a roughly triangular-shaped property covering approximately 1.86 acres. The site is occupied by three condo structures with grass-covered yard areas, landscaping plants, and few young to mature trees surrounding the buildings. The ground surface within the site is relatively level to gently sloping. The site is bound to the east by Elm Street, to the west by 45' Street SW, and to the south and north by existing residential properties. We understand that the subject structure (330 Building) has been experiencing ongoing settlement. A recent elevation survey indicated settlement on the order of up to 4.9-inches within the eastern portion of the structure relative to the western portion of the building. Observations within one third level unit indicated hairline cracking in the drywall, sloping floors, and out of plumb doors. Additionally, we observed some minor separation on the exterior brick veneer on the eastern side of the building. Subsurface Conditions Geology: The geologic units for this area are shown on the Geologic map of the Everett 7.5 minute quadrangle, Snohomish County, Washington, by Minard, J.P., (USGS, 1985). The site is mapped as Qvt (Glacial Till)with Qva(advanced outwash) in the near vicinity. The glacial till is described as a nonsorted mixture of clay, silt, sand,pebbles, cobbles, and boulders. Qva is described as well-sorted sand and gravel deposited by streams issuing from advancing ice sheet. Our explorations generally encountered undocumented fill underlain light brown to gray, fine to medium sand with varying amounts of gravel and silt, consistent with the descriptions of advanced outwash deposits. Explorations: The subsurface conditions within the site were explored on March 5, 2019 by performing four hand-augered explorations and four geotechnical borings. The approximate locations of our explorations are shown on the Schematic Site Plan in Figure 2. A geologist from NGA was present during the explorations, examined the soils and geologic conditions encountered, obtained samples of the different soil types, and maintained logs of the explorations. For the borings, a Standard Penetration Test(SPT) was performed on each of the samples during drilling to document soil density at depth. The SPT consists of driving a 2-inch outer-diameter, split-spoon sampler 18 inches using a 140-pound hammer with a drop of 30 inches. The number of blows required to drive the sampler the final 12 inches is referred to as the "N" value and is presented on the boring logs. The N value is used to evaluate the strength and density of the deposit. V t NELSON GEOTECHNICAL ASSOCIATES, INC.