§ 15.01.560. Reinforced concrete pipe.

Reinforced concrete pipe (RCP) shall comply with the requirements of ASTM C-76 with bell and spigot rubber gasket type joints for sanitary sewers and storm drain lines. For hydraulic design considerations, a Mannings n value of 0.012 for storm drain and 0.013 for sewer shall be used.

1.

RCP bell and spigot joints. Bell and spigot joints, including rubber gaskets, shall conform to the requirements of the latest revision of ASTM Designation C-443. The pipe joint shall be so designed as to provide for self-centering, and when assembled, to compress the gasket to form a watertight seal. The gasket shall be confined in a groove on the spigot, so that pipe movement or hydrostatic pressure cannot displace the gasket.

2.

RCP pipe installation. All pipe installation shall precede upgrade on a stable foundation, with joints closely and accurately fitted. Rubber gaskets shall be fitted properly in place, and care shall be taken in joining the pipe units to avoid twisting of gaskets. Joints shall be clean and dry and a joint lubricant as recommended by the pipe supplier shall be applied uniformly to the mating joint surfaces to facilitate easy positive joint closure.

Pipe shall be installed with uniform bearing under the full length of the barrel, with suitable excavations being made to receive pipe bells.

Select material shall be compacted around the pipe to firmly bed the pipe in position. If adjustment of position of a pipe length is required after being laid, it shall be removed and rejointed as for a new pipe. When laying is not in progress, the ends of the pipe shall be closed with a tight fitting stopper to prevent the entrance of foreign material.

In addition to the above requirements, all pipe installation shall comply with the specific requirements of the pipe manufacturer.

Where pipe product is provided with a joint system intended to allow for segmental installation of piping materials, joints shall be closed tightly such that gasket system is fully engaged and no more than one-half inch of gap section between overlapping joint material (bell and spigot or another approved method) is visible via a televised inspection methods. Contractor shall meet with city designated inspection representative prior any construction commencing to review city standards relative to installation of piping system.

3.

Gravel foundation for RCP pipe. Wherever the subgrade material does not afford a sufficiently solid foundation to support the pipe and superimposed load, and/or where groundwater must be drained, the subgrade shall be excavated to such depth as may be necessary and replaced with gravel compacted into place.

Gravel for concrete pipe foundation shall be clean gravel with one hundred percent passing a one-and-one-half-inch screen and five percent passing a three-fourths-inch sieve.

4.

RCP pipe bedding. All pipe sewers and drains shall be protected from lateral displacement and possible damage resulting from impact or unbalanced loading during backfilling operations by being adequately bedded.

A groove shall be excavated in the bottom of the trench to receive the bottom quadrant of the pipe. Before preparing the groove, the trench bottom shall be excavated or filled and compacted to an elevation sufficiently above the grade of the pipe so that, when completed, the pipe will be true to line and grade. Bell holes shall be excavated so that only the barrel of the pipe receives bearing from the trench bottom.

Pipe bedding materials placed at any point below the mid-point of the pipe shall be deposited and compacted in layers not to exceed eight inches in uncompacted depth.

Deposition and compaction of bedding materials shall be done simultaneously and uniformly on both sides of the pipe. Compaction shall be accomplished with hand mechanical compactors. All bedding materials shall be placed in the trench with hand tools or other approved method in such a manner that they will be scattered alongside the pipe and not dropped into the trench in compact masses. Bedding materials shall be loose earth, free from lumps, sand or gravel, free from rocks larger than three-inch diameter, with all materials free from roots, sod, or other organic matter.

In the event trench materials are not satisfactory for pipe bedding, modified bedding will be required. Modified bedding shall consist of placing compacted granular material on each side of and to the level of twelve inches above the top of the pipe.

Modified bedding material shall be graded as follows: one hundred percent passing a one-inch screen and no more than five percent passing a No. 4 sieve.

(Ord. No. 2007-07-31, §§ 6.5—6.5.4, 7-10-2007; Ord. No. 2010-11-24, § 2, 11-23-2010; Ord. No. 2011-06-17, § 1, 6-28-2011)