8417 EVERGREEN WAY Geotech Report 2022-10-25

Geotechnical Engineering Report- Revised l��rracon Proposed CFT Retail Everett,Washington February 1, 2018 Terracon Project No. 81185002 The use of a vapor retarder or barrier should be considered beneath concrete slab-on-grade floors that will be covered with wood, tile, carpet or other moisture-sensitive or impervious coverings, or when the slab will support equipment sensitive to moisture. When conditions warrant the use of a vapor retarder, the slab designer and slab contractor should refer to ACI 302 and ACI 360 for procedures and cautions regarding the use and placement of a vapor retarder/barrier. 4.4.2 Construction Considerations On most project sites, the site grading is generally accomplished early in the construction phase. However, as construction proceeds, the subgrade may be disturbed due to utility excavations, construction traffic, desiccation, rainfall,etc.As a result,the floor slab subgrade may not be suitable for placement of the base course and concrete slab, and corrective action may be required. All floor slab subgrade areas should be moisture conditioned and properly compacted to the recommendations in this report and then thoroughly proofrolled with a loaded tandem-axle dump truck prior to final grading and placement of the base course. If subgrades are not accessible to a dump truck, a Terracon representative should evaluate subgrade condition by visual observation and the use of a footing probe. Particular attention should be paid to high traffic areas that were rutted and disturbed earlier and to areas where backfilled trenches are located. Areas where unsuitable conditions are located should be repaired by removing and replacing the affected material with properly compacted structural fill. 4.5 Seismic Considerations Code Used Site Classification 2015 International Building Code(IBC)' D Site Latitude 47.92061°N Site Longitude -122.22849°W Ss—Short Period Spectral Acceleration for Site Class B 1.420 g Si — 1-Second Period Spectral Acceleration for 0.545 g Site Class B Fa—Short Period Site Coefficient 1.000 F„— 1-Second Period Site Coefficient 1.500 1. The 2015 International Building Code indicates that the seismic site classification is based on the average soil and bedrock properties in the top 100 feet. The current scope does not include a 100- foot soil profile determination. This seismic site class definition considers that soils encountered at depth in our boring continue below the termination depth. Additional exploration to deeper depths would be required to confirm the conditions below the current depth of exploration. Responsive Resourceful Reliable 13