(a) The subgrade shall be free of sod, vegetative or organic matter, soft clay, and objectionable materials for a depth of at least two (2) feet below the finish surface.
(b) The subgrade shall be properly rolled, shaped, and compacted in accordance with the State of Ohio Department of Transportation Specifications. All soft areas shall be removed and replaced with suitable material to achieve the required approval. Backfills over sewers, culverts and underground utilities in the roadway shall also meet the specifications in ODOT's Construction and Material Specifications.
(c) Subbase grade tolerance shall be no more than one (1) inch in sixteen (16) feet, and shall be subject to the approval of the City/County Engineer.
(d) Where granular subbase is not a part of the pavement design, and rock, shale or coal is encountered, the subgrade shall be excavated to a depth of 2 feet below the surface of the subgrade for the cross section width of the roadway between points 1 foot beyond the shoulders. The additional excavation shall be filled with suitable embankment material.
(e) Where granular subbase is a part of the pavement design, and rock, shale or coal is encountered, the subgrade shall be excavated to a depth of 18 inches below the subbase for the cross section width of the roadway between points 1 foot beyond the shoulders. The additional excavation shall be filled with suitable embankment material.
(f) Approval of the sub-grade must be obtained from the City/County Engineer prior to the application of the base course.