7431 EVERGREEN WAY TACO BELL 2018-01-01 MF Import

GEOTECHNICAL ENGINEERING STUDY Taco Bell Corporation April 29, 1993 =u�i E-6140 Page 9 The adequacy of site pavements is related in par 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 Pr�paration section of this report. This means that at least the top tweive (12) inches of the subgrade should be compacted to 95 percent of the maximum dry density (per ASTM D-1557-78). It is possiblct 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 ;:tabilize these Iocallzed areas. The following pavement sections are recommended for lightly-loaded areas consisting of parking stalls experiencing daily traffic of 100 cars: • 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. The following pavement sections are recommended for heavier traffic areas consisting of roadways subjected to a minimum daily traffic of 1,000 cars and five applications of 18,000- pound single-axle load trucks: � Three inches of AC over six inches of CRB, or • Two inches of AC over four inches of ATB. Asphaitic Cement (AC), Asphalt Treated Base (ATB�, and Crush�3d Rock Base (CRB) matgriais should conform 4o 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. In addition, the above pavement sections are based on a 10-year desig� period. It is recommended that concret� slabs which are placed directl�� over a native soil subgrade and are subject to vehicle traffic loads be at least six inchss in thickness. It is also suggested that nominal reinforcement such as "6x6-10/10" welded wire mesh be employed, at near midpoint, in new exterior concrete slabs and paving. Earth Consultants, Inc.