4815 EVERGREEN WAY 2016-01-01 MF Import

JP Morgan Chase Apri129, 2010 Geot echnical Investigat ion Proposed Chase Bank Everett, WA PSI Report No. 0704186 4.10 PAVEMEN7 In lieu of project-spzcific traffic estimates, the following pavement design recommendations are based on our experience with similar facililies and subgrade conditions. For automobile parking areas, we recommend a pavement section consisting of 3 inches of asphaltic concrete (AC) over 6 inches of crushed rock base (CRB). For truck traffic areas, the pavement seclion should consist of 4 inches of AC over 8 inches of CRB. These recommended pavement �ections are based on the assumption that the subgrade consists of firm, undisturbed soil or fine-grained structural fill and that the pavemeni will be constructed during the dry summer months. Proofrolling should be used to evaluate pavement subgrade. Any soft areas disclosed by proofrolling will likely require overexcavation and replacement with structural fill. Some contingency should be provided for the repair of any soft areas. If pavement construction is scheduled for the wet season, it wiil be necessary to increase the above-recommended hase c�urse sections. Permanent, properly installed drainage is also an essential aspect of pavement design and construction. A!I paved areas shouid have positive drainage to prevent ponding of surface water and saturation of the base course. This is particulariy important in cut sections or at low points within the paved areas, such as in sui;ken loading dock areas or around stormwater catch basins. Fftective means io prevent saturation of the base course including installing subdrain systems below sunken loading docks and weep holes in the sidewalls to catch basins. 4.11 GENERAL SEIBMIC DESIGN INFORMATION Based on the subsurface condilions at the site and our review of the IBC, we recommend using soil Site Class C to evaluate the seismic design of the structure. 5.0 ADDITIONAL SERVICES Because the future performance and inte�rity of the struclural elements will depend largely on prop� r site preparation, drainage, fill placement, and construction procedures, monitoring and tes �eotechnical special insFectior) by experienced geotechnical personnel should be con.,,. red an integral part of the design process. Consequently, we recommend that PSI be retained to provide the following post-investigation services: • Review construction plans and specifications to verify that our design criteria presented in this report have been properly integrated into the design • Attend a pre-construction conference wi!h the design team and contractor to discuss important geotechnical related constructi��n issues • Observe exposed subgrade rdter completion of stripping and mass grading to confirm that suitable soil conditions hav� been reached Mj' s