9606 19TH AVE SE McDONALDS Geotech Report 2018-01-02 MF Import

GEOTECHNICAL ENGINEERING STUDY McDonald's Corporation E-6893-1 June 9, 1995 Page 10 Pavement Areas The adequacy of site pavements is related in part to the condition of the underlying subgrade. To provide a properly prepared subgrade for pavements, we recommend the subgrade be treated and prepared as described in the Site Preparation and Grading section of this report. This means at least the top twelve (12) inches of the subgrade should be compacted to 95 percent of the maximum dry density (per ASTM 1557-78). It is possible that some localized areas of soft, wet or unstable subgrade may still exist after this process. Therefore, a greater thickness of structural fill or crushed rock may be needed to stabilize these localized areas. We recommend the following pavement section for lightly loaded areas: • Two inches of Asphalt Concrete (AC) over four inches of Crushed Rock Base (CRB) material, or • Two inches of AC over three inches of Asphalt Treated Base (ATB) material. Heavier truck -traffic areas will require thicker sections depending upon site usage, pavement life and site traffic. As a general rule, the following sections may be considered for truck -trafficked areas: • Three inches of AC over six inches of CRB, or • Three inches of AC over four inches of ATB. Asphalt Concrete (AC), Asphalt Treated Base (ATB), and Crushed Rock Base (CRB) materials should conform to WSDOT specifications. All rock base should be compacted to at least 95 percent of the ASTM D-1557-78 laboratory test standard. It should be noted that parking stall pavement sections assume no truck traffic. Emth Ctauuhanta, Inc.