(A) After all earth work is substantially complete and all drains installed, the subgrade shall be brought to the lies and grades shown on the plans or as may be otherwise approved in accordance with these standards. Such portions shall be known as subgrades.
(B) Unless otherwise provided, the upper six inches of all subgrade shall be uniformly compacted to at least 95% standard density as determined by the provisions of AASHO, T99, (American Association State Highway Offices), “Compaction and Density of Soils.” A six-inch subgrade fill next to concrete shall be two-inch stone or its equal, then rolled with not less than a ten-ton roller. During subgrade preparation and after its completion, adequate drainage shall be provided at all times to prevent water from standing on the subgrade. Subgrades shall be so constructed that it will have as nearly as possible uniform density throughout. After compaction and final grading, the subgrade shall be finished with a three-wheel roller weighing not less than ten tons. At areas not accessible to the roller, the required compaction shall be obtained with mechanical tamps and vibrators. All soft yielding or otherwise unsuitable material which will not compact properly shall be removed. All rock encountered shall either be removed or broken off to conform with the required cross section. Any holes or depressions resulting from the removal of such unsuitable material shall be filled with satisfactory material and compacted to conform with the surrounding subgrade surface. No placement of pavement shall be permitted on uninspected or unapproved subgrade and at no time when the subgrade is frozen or muddy. No hauling shall be done nor equipment moved over the subgrade when its condition is such that undue distortion results. If these conditions are present, the subgrade shall be protected with adequate plant runways, mats or other satisfactory means if hauling is done thereon. The subgrade shall be prepared sufficiently in advance to permit proper inspection so that the final elevation may be checked with a scratch template and compaction checked. All utility excavations under the pavement shall be backfilled with Grade “B” borrow, and construction shall conform to Section 211 of the “Standard Specifications” or compacted thoroughly by other means.
(`87 Code, § 7-27) (Ord. 1979-4A, passed 4-10-79; Ord. 1978-8A, passed 8-8-78)