5200 EVERGREEN WAY SEPA 017 - 010 Geotech Report 2025-04-23

Subsurface Exploration, Geologic Hazards, and Former Brien Ford Preliminary Geotechnical Engineering Report Everett, Washington Preliminary Design Recommendations Resistance to lateral loads for a pipe pile-supported foundation should be provided by using batter piles. The lateral resistance of batter piles would be equal to the horizontal component of the axial pile load. The maximum batter recommended is 1H:4V. A structural engineer should determine the number, spacing, and layout of the piles. 11.2 Pile Inspections The actual total length of each pile may be adjusted in the field based on required capacity and conditions encountered during driving. Since completion of the pile takes place below ground, the judgment and experience of the geotechnical engineer or their field representative must be used as a basis for determining the required penetration and acceptability of each pile. Consequently, use of the presented pile capacities in the design requires that the installation of all piles be observed by a qualified geotechnical engineer or engineering geologist from our firm, who can interpret and collect the installation data and examine the contractor's operations. AESI, acting as the owner's field representative, would determine the required lengths of the piles and keep records of pertinent installation data. A final summary report would then be distributed following completion of pile installation. 12.0 PAVEMENT RECOMMENDATIONS We understand that once the excavation is backfilled with structural fill the area will receive a new pavement section. At this time we do not anticipate that new paving will be completed on public streets and will generally be over the excavation area. If new paving is planned on public streets we should be allowed to make situation-specific paving recommendations. After the area to be paved is backfilled with structural fill and the subgrade soils are approved by an AESI representative, the pavement section should follow the project plans and specifications. The crushed rock base courses should be compacted to 95 percent of maximum density. All paving materials should meet gradation criteria contained in the current Washington State Department of Transportation (WSDOT) Standard Specifications. 13.0 PROJECT DESIGN AND CONSTRUCTION MONITORING Our report is preliminary since project plans were not available at the time this report was prepared. We recommend that AESI perform a geotechnical review of the plans prior to design completion. We are also available to provide geotechnical engineering and monitoring services during construction. The integrity of the foundation underpinning system depends on proper site preparation and construction procedures. In addition, engineering decisions may have to be May 16,2017 ASSOCIATED EARTH SCIENCES,INC. AWR/Id-160594V003-2-Projects120160594\KV\WP Page 13