801 E CASINO RD Geotech Report 2022-10-25

Cascade Nigh School Subsurface Exploration and Synthetic Turf Field Geotechnical Engineering Report Everett, Washington Design Recommendations specific underdrain requirements and are available to provide geotechnical recommendations related to underdrain design on request. 8.3 Subsurface Drain Trenchin>; Construction of new subsurface drains will require trenching into the underlying native sediments and existing fill. As part of this study, borings were advanced to provide information on sediment density and ease of trenching. The existing fill soils within the proposed development area are in a very loose to dense condition and should therefore be backhoe-excavated with limited difficulty. The native lodgement till sediments are very dense, and will require the use of heavier equipment to excavate, and slower production rates should be expected. 8.4 Subfield Drainage Aegre-Rate We anticipate that up two layers of drainage aggregate will be placed and compacted over the prepared field subgrade and below the turf. The drainage aggregate is a very specialized manufactured product that provides a compactable, stable working surface while maintaining a high minimum infiltration rate. The drainage aggregate should be tested for gradation and approved by the field designer prior to delivery onsite. Daily sampling and gradation testing during placement is recommended to verify continued compliance with project specifications and approved submittals. The material should be kept moist during transport, placement, and compaction to reduce the potential for fines segregation. Once placed and compacted, the material should be field-tested for density and permeability. If field permeability test results are below the minimum project requirements, the material may need to be loosened and recompacted or removed and replaced with materials that meet the minimum permeability requirements. 9.0 PROJECT DESIGN AND CONSTRUCTION MONITORING We are available to provide additional geotechnical consultation as the project design develops and possibly changes from that upon which this report is based. We recommend that AESI perform a geotechnical review of the plans prior to final design completion. in this way, we can verify that our earthwork recommendations have been properly interpreted and implemented in the design. We are also available to provide geotechnical engineering and monitoring services during construction. The integrity of the athletic field depends on proper site preparation and construction procedures. In addition, engineering decisions may have to be made in the field in the event that variations in subsurface conditions become apparent. Construction monitoring March 20, 2017 ASSOCIATED EARTH SCIENCES, INC. DDV/pc-170081EO01-2—ProjectsJ201700811KEW Page 9