801 E CASINO RD Geotech Report 2022-10-25

Cascade High School Subsurface Exploration and Synthetic Turf Field Geotechnical Engineering Report Everett, Washington Project and Site Conditions 2.0 PROJECT AND SITE DESCRIPTION The project site consists of the existing track and field north of the school buildings at Cascade High School in Everett, Washington. The existing facility is a natural turf football field surrounded by a urethane -surfaced track. The existing field is relatively flat, with overall vertical relief of approximately 1 foot based on elevation ground shots that were provided to US. Proposed improvements include removal of existing natural turf and construction of a new underdrain system and synthetic turf. No field lighting or other substantial structures are planned. 3.0 SITE EXPLORATION We completed six hollow -stem auger borings at the locations shown on Figure 2. The borings were completed by advancing a 04-inch inside -diameter, hollow -stem auger with a track -mounted drill rig. During the drilling process, samples were obtained at generally 2.5- to 5-foot-depth intervals. The exploration borings were continuously observed and logged by an engineering geologist from our firm. The various types of soils, as well as the depths where characteristics of the soils changed, are indicated on the exploration logs presented in the Appendix of this report. The exploration logs presented in the Appendix are based on the field logs, drilling action, and inspection of the samples secured. Our explorations were approximately located by measuring from known site features shown on the "Existing Conditions" site plan that was provided to us by D.A. Hogan, dated February 8, 2017. Because of the nature of exploratory work, extrapolation of subsurface conditions between field explorations is necessary. Differing subsurface conditions may be present due to the random nature of natural sediment deposition and the alteration of topography by past grading and filling. The nature and extent of any variations between the field explorations may not become fully evident until construction. If variations are observed at the time of construction, it may be necessary to re-evaluate specific recommendations in this report and make appropriate changes. Disturbed, but representative samples were obtained by using the modified Standard Penetration Test (SPT) procedure. This test and sampling method consists of driving a 2-inch outside -diameter, split -barrel sampler a distance of 18 inches into the soil with a 140-pound hammer free -falling a distance of 30 inches. The number of blows for each 6-inch interval is recorded, and the number of blows required to drive the sampler the final 12 inches is known as the Standard Penetration Resistance ("N") or blow count. If a total of 50 is recorded within one 6-inch interval, the blow count is recorded as the number of blows for the corresponding number of inches of penetration. The resistance, or N-value, provides a measure of the relative March 20, 2017 ASSOCIATED EARTH SCIENCES, INC. DDV/pc-170081E001-2—Projects�20170081JKEJWP Page 2