Backfill with Excavated Material. The excavated material can be used for backfill provided that such material consists of loam, clay, sand, fine gravel, or other materials which are suitable for backfilling and is approved by the Employer’s Representative. If suitable material for refilling is not available from already excavated material the Contractor shall import material of approved quality as directed by the Employer’s Representative.
Backfill with Excavated Material. The excavated material can be used for backfill provided that such material consists of loam, clay, sand, fine gravel, or other materials which are suitable for backfilling and is approved by the Employer’s Representative. If suitable material for refilling is not available from already excavated material the Contractor shall import material of approved quality as directed by the Employer’s Representative. Care shall be taken during backfilling not to injure or disturb the pipes, joints or coating. Filling shall be carried out simultaneously on both sides of the pipes so that unequal pressure does not occur. The Contractor shall be responsible to ensure that the water content of the soil shall be kept as near the optimum moisture content as possible. Regular measurement of the field dry density shall be taken by the Contractor at various levels in the backfilling as required by specifications and the Employer’s Representative. Any backfill which fails to achieve the required degree of compaction shall be re- excavated, replaced and re-compacted to the required density, all at the Contractor’s cost. Only mechanical compaction shall be done unless otherwise specified or approved by the Employer’s Representative. No mechanical plant other than approved compacting equipment shall run over or operate within the trench until backfilling has reached its final level or the approval for the Employer’s Representative has been obtained. Walking or working on the completed pipeline shall not be permitted unless the trench has been filled with the specified bedding and backfilling up to height of at least 300 mm over the top of the pipe except as may be necessary for tamping, etc., during backfilling work. The trench shall be refilled so as to build up to the original ground level, keeping due allowance for subsequent settlement likely to take place. The surface of the refilled excavations shall be left slightly higher than the adjacent ground and shall be maintained by the Contractor to a smooth even slope. Should any subsidence take place either in the filling of the trenches or near about it during the works the Contractor shall make good the same at his own cost. All the surplus excavated stuff (including rock) will be the Contractor’s property and he will be responsible to make proper arrangement for disposal of the same. Suitable surplus excavated material shall be used to fill in any low spots above the pipeline as instructed by the Employer’s Representative. Su...
