227 No. 53 over 3 in. of coarse aggregate No. 5 or No. 8. Geotextile Type 2B in accordance 80 with 918.02(c) shall be placed above and below the layer of No. 5 or No. 8 coarse aggregate. In areas where shallow u tilities are encountered or chemical modification is not allowed, the Contractor may submit a request to the Engineer to substitute Type IC for Type IBC or Type IBL. Where the strength or density and moisture control option is used, compaction of embankment areas shall be in accordance with 203.23. In cut and transition areas, the top lifts shall be removed, and the bottom 6 in. compacted in-pl ace in accordance with 90
203.23 The excavated material shall then be replaced and compacted in 6 in. lifts in
accordance with 203.23. Removal of the lif ts may be waived and only the upper 6 in. compacted in accordance with 203.23 when it is determined, through testing in accordance with 203.24, that the lo wer lifts comply with 203.23. In sections where rock, shale, sandstone or its mixtures are encountered, these materials shall be undercut 24 in. belo w the subgrade elevation and replaced with coarse aggregate No. 53 or No. 73 and compacted in accordance with 301.06. Geotextiles used shall be in accordance with 918.02. All irregularities and holes shall be graded with either coarse aggregate No. 53 or No. 73. If an aggregate base is part of the HMA pavement structure, the 24 in. excavation depth shall be reduced by the thickness of the aggregate base. The 3 in. compacted aggregate as part of the subgrade treatment Type V shall be compacted to 100% prior to the placement of the pavement. When conditions are encountered below the specified subgrade treatment depth that prevent achieving the specified subgrade compaction, such conditions shall be corrected in accordance with 203.09, or as directed. 110 Proofrolling shall be performed in accordance with 203.26.
207.05 Method of Measurement
Subgrade treatment will be measured in both cut and fill areas by the square yard per type. Geosynthetic specified for use in addition to that required for the specified subgrade treatment will be measur ed in accordance with 214.05. The undercutting of rock, where encount ered, will be measur ed in accordance with 203.27(b). Testing, sampling, coarse aggregates , chemicals for modification, water, excavation, geogrid, geotextile, and geocell confining system for specified subgrade treatment types will not be measured. 207.05
207.06 Basis of Payment
The accepted quantities of subgrade treatment will be paid for at the contract unit price per square yard per type, complete in place. In areas where shallow utilities are 130 encountered or the Contractor elects to use Type IC for Type IBC or Type IBL, payment will be made at the price of Type IBC or Type IBL. The undercutting of rock, where encounter ed, will be paid for in accordance with 203.28. Payment will be made under: Pay Item Pay Unit Symbol 140 Subgrade Treatment, Type _____ ............................................. SYS The cost of subgrade treatments including testing, sampling, coarse aggregates, chemicals for soil modification with cement or lime, water, excavation, geogrid, geotextile and geocell confinement system for specified subgrade treatment types shall be included in the cost of the pay item. The cost of excavation and grading of existing railroad ballast and railroad bed material shall be included in the cost of subgrade treatment, Type V. Geosynthetic specified for use in addition to that required for the specified subgrade treatment will be paid for in accordance with 214.06. Where conditions exist below the specified subgrade compaction depth that prevent achieving the specified compaction, payment for correcting such conditions will be made based on the directed method of treatment.