1999-338A - Laserfiche WebLink

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C-1 made without bedding material interference. 2) At the option of the Contractor, Class B Bedding may be used in place of Class C (Ordinary Bedding) provided that the exercise of this option shall create no additional expense to the Owner. The Contractor shall notify the Engineer in writing of those portions of the project on which he proposes to exercise this option. CLASS C (ORDINARY BEDDING) 1) The bottom of the trench shall be hand shaped to provide a firm bedding for the utility pipe. The utility shall be firmly bedded in undisturbed firm soil. The bedding shall be shaped so that the pipe will be in continuous contact therewith for its full length and shall provide a minimum bottom segment for the pipe equal to 0.6 of the outside diameter of the barrel. Excavation under the bell shall be sufficient so that the bell does not support the pipe and the joint can be made without interference. D. UNSUITABLE BEDDING MATERIAL 1) Class C Bedding shall be used for all pipeline construction unless otherwise shown on the Drawings or unless unsuitable material is encountered at the bedding surface. In the event that the materials encountered at normal bottom of trench excavation are, in the judgment of the Engineer, unsuitable to act as foundation for the pipe, such material shall be excavated for the full width of the trench to the depth necessary to obtain a suitable foundation. The Engineer will notify the Contractor, in writing, of the necessity for and extent of the material to be removed and the Contractor shall remove such unsuitable material as soon as possible and backfill in accordance with the requirements for Class B Bedding. All unsuitable material shall be disposed of by the Contractor. PIPE TRENCH BACKFILL A. INrrLkL BACKFILL 1) Initial backfill shall be placed as soon as possible after laying the pipe and shall maintain a pace with the pipe laying so that no more than five pipe joints separate laying and backfilling operations. Initial back rill shall include all haunching and backfill from the top of the bedding to a compacted depth of twelve inches over the pipe. All haunching and backfilling shall be done in the dry. 2) Initial backfill shall be done as specified below: (a) Haunching of the pipe shall be by hand placement and compaction of material in maximum 4 inch layers from the bottom of the trench to the springline of the pipe, taking care to fill all voids below and around the pipe. Backfilling shall be carefully continued in layers riot exceeding 6 inches in thickness for the full trench width until the compacted fill is 12 inches above the top of the pipe. (b) During initial backfilling the fill shall be deposited evenly along both sides of the pipe from a height not to exceed 2 feet above 2Q.4 ima