(A) In backfilling, fine material free from lumps and stone selected from the spoil shall be thoroughly compacted around and under the substructure to the upper level of the substructure. Above the upper level of the substructure, backfill material shall be placed to the subgrade of the pavement in lifts consistent with the type of soil involved and the method of consolidation being used. Broken pavement, large stones, roots and other debris shall not be used in the backfill. Each lift shall be flooded, jetted, rolled or pneumatically tamped or a combination of these methods shall be used depending upon the type of soil involved to compact the backfill material. Such backfill shall be done in a manner that will permit the restoration of the surface to a condition equivalent to that in which it was prior to the excavation. The Director of Public Works may require soil tests to be furnished by a recognized soil-testing laboratory or registered professional engineer specializing in soil mechanics when, in his opinion, backfill for any excavation is not being adequately compacted. Should it be determined by tests that a "relative compaction" of 95% has not been obtained, the Director of Public Works may require that any or all of the backfill be removed and recompacted as necessary to obtain the required 95% relative compaction. All expense of such tests shall be borne by the permittee.
(B) Unless otherwise authorized by the Director of Public Works, all trenches or other excavations in the existing or future traveled roadway shall be backfilled with one sack slurry sand vibrated into place.
(C) Whenever native backfill is allowed by the city, it shall be mechanically tamped and compacted to 95% relative density per ASTM Specification D-1557. The engineer may allow 90% relative density in parkways and other locations.
(D) Violation of this section shall be deemed an infraction.
('64 Code, § 19-54) (Ord. 164, passed 12-20-60) Penalty, see § 10.97