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TRENCHING & BACKFILL 02 2020-8 B. Initial backfill and bedding shall be carefully packed under the haunches of the pipe and brought up simultaneously on both sides so as to obviate any displacement of the pipe from its true alignment. Bedding shall be compacted in layers not more than eight (8) inches in thickness in a manner that will preclude moving the pipe, to not less than 95% of maximum dry density as determined by the procedure set forth in ASTM Designation D1557. Jetting of backfill material will not be permitted. C. Select backfill above the initial backfill shall be placed in loose lifts not exceeding eight (8) inches in thickness before compaction, and compacted by the use of pneumatic tampers or other mechanical means approved. Water or dry, as required, to bring the soils as close as practicable to the optimum moisture content for proper compaction. Compaction equipment or methods that produce horizontal or vertical earth pressures which may cause excessive displacement or may damage the pipeline will not be permitted. Lifts of backfill shall be compacted to not less than 95% of maximum dry density as determined by the procedure set forth in ASTM Designation D1557. Jetting of backfill material will not be permitted. D. For flowable CDF, compaction is not necessary for placement. Trench sections may be filled in one lift above the initial backfill material. Trench sections may be filled in one lift above the initial backfill material in a manner which will; not disturb the line, prevent a misalignment, movement, floatation of or otherwise damage the utility. E. Backfill will be inspected and tested by the Engineer during placement. Contractor shall cooperate with the Engineer and shall provide working space for such tests in his operations. Backfill not compacted in accordance with these specifications shall be recompacted, or removed as necessary and replaced to meet specified requirements prior to proceeding with the work. 3.05 GENERAL BRACING AND SHORING A. The Contractor shall furnish, place and maintain such bracing and shoring as may be required to support the sides of the excavations for the proper protection of workmen; to facilitate the work; and to prevent damage to adjacent structures or facilities. B. Upon completion of the work, all bracing and shoring shall be removed, unless otherwise directed by the Engineer. Current requirements are for a maximum depth of 5 feet without CAL-OSHA approved shoring. 3.06 SPECIAL REQUIREMENTS FOR SHORING AND EXCAVATING IN BAY MUD A. Trenches or other excavations, where the distance from the existing grade to the bottom of the excavation exceeds eight (8) feet, shall be interlocking, continuous solid sheathing. Said sheathing shall be designed to resist an equivalent fluid pressure having a density of at least 100-lbs.per cubic foot for the full height of the trench and shall be installed for the full depth of trench and to a sufficient depth below the bottom of the excavation to prevent heaving of the bottom, and