2205 BROADWAY 2016-01-01 MF Import

LSI -ADAPT Erosion Potendal The su�ciai site soils contain a significant amount oC fines and thus may be highly prone to erosion. To contain silt-laden runoff from leaving the site during construction, we recommend that silt fencing tx set up around the perimeter of the site in accordance with Ciry of Everett requirements. Pavement Arcas The adequacy of site pavcments is related to the condition of the undetlying subgrade. To pmvide a properly prepared subgrade for pavements, the subgrade should be treated and prepared as described in the Site Prepazation and General Earthwork Section of this report. This means at least the top 12 inches of the subgrade should be compacted to 95 percent of the Maximum Dry Densiry (per ASTM D-1557). It is possible that some localized arcas of loose, wet, or unstable subgrade may exist after this process. Thercfore, a greater thickness of structural fill or crushed rock may be needed to stabilize these localized areas. The following pavement section for lighUy-loaded areas can be used: • Two inches of Asphalt Concrete (AC) over four inches of Crushed Rock Basc (CItB) material,or • Two inches of AC ovcr Uvee inches of.4sphalt Treated 13ase(ATB)material. Heavier hvck-traffic areas will require thicker sections dcpending upon site usage, pavement life and sitc traffic. As a general rule,you may consider for Wck-traffic arcas lhe following sections: • Three inches of AC over six inches af CRB,or • Three inches of AC over four and one-half inches of.4TB. We will be pleased to assist you in developing appropriate pavement sections for heary trafTc zoncs, if needed. CONCLUSION Ir conclusion,we fecl that the proposed conshvetion is compatible with the existing site conditions provided that the foregoing recommcndations are implementcd. 1Vc reconuncnd that LSI - ADAPT be retaincd throughout Qic projcct to assurc compliancc��-iAi thcsc spccifications. IL51•ADAP7 Job No.WA02-8121 pa8e�� l August 6,2002