Attachment 3_02222_Trench.doc

SECTION 02222

EXCAVATING, BACKFILLING, AND COMPACTION FOR UTILITIES

PART 1 GENERAL

1.01 SCOPE

This work consists of trench excavation, backfilling and compaction for utilities.

PART 2 PRODUCTS

2.01

BEDDING MATERIAL

A. Sand shall be clean free flowing granular material, free of vegetative matter with 100 percent finer than the No. 4 sieve, and with no more than six percent passing the No. 200 sieve.

B. Clean naturally rounded aggregate with a mix of particle sizes not less than 1/8 inch or greater than 1/2 inches. This material is commonly called pea gravel.

PART 3 EXECUTION

3.01

GENERAL

Trenching shall be performed to the lines, grades, and dimensions SHOWN ON THE DRAWINGS to provide the minimum required cover and separation between lines. Excavation shall be considered unclassified regardless of material encountered.

3.02

EXISTING UTILITIES

Prior to beginning trenching, the Contractor shall locate all existing underground utilities intersecting or parallel to the trench. Existing utilities shall be located by means of an electronic pipe and cable locator and the location identified by spray painting the ground surface.

3.03

RESPONSIBILITY FOR UTILITIES

Any existing underground utilities identified on the plans or identified by the Contractor, as required above, shall be repaired or replaced at no additional cost to the Government if damaged.

3.04

SAW CUTTING

Before trenching through concrete, asphalt concrete, chip sealed or oiled areas, the edges of all trenches shall be saw cut to sharp clean vertical edges.

3.05

EXCAVATED MATERIAL

Trench excavation shall be placed in a neat pile adjacent to the trench a sufficient distance to prevent cave‑ins. Spoils pile shall not obstruct traffic. Excess excavation or excavation not suitable for backfill shall be hauled off Government land.

3.06

BEDDING

All pipes shall be bedded in sand AS SHOWN ON THE DRAWINGS.

3.07

BACKFILL

Native material may be used as backfill As SHOWN ON THE DRAWINGS provided it contains no rocks larger than 6 Inches In greatest dimension. Native backfill shall be compacted In 12 inch loose measure lifts to 90 percent of AASHTO T‑180 Method C, except in paved areas where backfill shall be compacted to 95 percent of AASHTO T‑180 Method C and placed in 6 inch lifts.

3.08 CONCRETE (if applicable) Concrete shall be replaced when trenching through concrete walkways. Concrete shall conform to the requirements of Section 03300.

3.09

SAFETY

A. Trenches shall be sloped or shored as required by the California State Division of Safety and Health.

B.

Contractor shall erect barriers around trench excavations to prevent accidents. Lights shall be placed from sunset to sunrise of the next day until excavation is entirely backfilled.

END OF SECTION

WATER DISTRIBUTION

DIVISION 2 02222-1

REPLACEMENT

ANGELES NATIONAL FOREST