COMPLIANCE INFO_1997-2002 - Laserfiche WebLink

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* City of Tracy minimum requirements. It is possible that site grading, utility line backfilling, and/or underground storage tank installation could alter the distribution of near -surface materials requiring reevaluation of the recommended pavement structural sections. It is our understanding that the City of Tracy will require that the R -Value for the subgrade soil be verified during construction with additional testing. The aggregate base should meet CALTRANS specifications for Class 2 base or the specifications for Processed Miscellaneous Base (PMB) as contained in the Standard Specifications for Public Works Construction. The above pavement sections are based upon the assumption that the subgrade is uniformly compacted to at least 90 percent relative compaction to a depth of 12 inches at the time of base placement. Final geotechnical observation and testing of subgrade should be performed just prior to the placement of aggregate base. Aggregate base should be compacted to at least 95 percent relative compaction. Site grading will be required to achieve plan grades and to provide uniform structural support. Recommendations for site grading are presented in the following subsections, while general guide specifications for placement of fill and backfill are presented in Appendix C. 6.9.1 Clearing and Grubbing Clearing and grubbing of the site will be required to remove all vegetation and unsuitable material prior to grading. Topsoil, and soil containing vegetation, organics and/or humus, should be removed and used in planters or disposed off-site. The roots of existing trees and/or brush in the construction area should be removed by over -excavation and replaced with compacted fill. It is essential that excavations created by removing vegetation roots and other unsuitable materials should be backfilled with clean fill soil and should be compacted in accordance with the requirements presented below. JN 4M7-095-01 U*=s* ?-o6jm%ftneo.a« M,