§ 11-141. Excavation, trench preparation and installation.

(a)

Where the pipe is laid below ground line, the trench shall be excavated to the required depth and width to allow sufficient room for tamping of backfill. The bottom of the trench shall be shaped to conform to the bottom of the pipe with recesses excavated to receive the bells where bell and spigot pipe are used. Where pipe is not laid in a trench, a uniform firm bed shall be made as specified above.

(b)

When rock is encountered in the trench, it shall be removed to minimum depth of six (6) inches below the pipe, and the excess depth shall be filled with a suitable material and compacted.

(c)

All unsuitable material, including soft and yielding material, shall be removed and replaced with suitable material and compacted to ensure a firm support.

(d)

The pipe shall not be laid in water or in unsuitable weather or trench conditions unless approved by the County Road Superintendent.

(e)

After each joint of pipe has been graded, aligned and placed in final position, the bedding material shall be deposited and compacted under and around each side of the pipe and back of the bell, or the end thereof, to firmly hold and maintain the pipe in proper position and alignment and backfilling operations.

(f)

No debris creating a clogging action shall be allowed to remain in the storm drainage system.

(g)

All storm drainage pipe, under any roadway improvement, shall be backfilled with SB-2, SB-3 base or material approved by the County Road Superintendent and compacted before the base and curb and gutter are constructed. The backfill base material shall be brought up evenly on each of the pipes to avoid displacement. Special care shall be taken to compact the material under the haunches of the pipe. The base material shall be compacted with mechanical equipment to at least ninety-eight (98) percent of the maximum density as determined by AASHTO T 180.

(h)

When culvert pipe is to be relayed, the construction procedures shall be in accordance with the AHTD Standard Specification requirements for relaying culvert pipe.

(i)

When structural plate pipe and arches are used, the materials and construction procedures shall be in accordance with the AHTD Standard Specification requirements for structural plate pipe and arches. Flared end sections may be used when approved by the County Road Superintendent.

(Ord. No. 91-9, Art. 1, § 5.02, 4-11-91; Ord. No. 99-32, Art. 1, 7-8-99)