R6/SPECIAL PROJECT SPECIFICATION
SECTION 649 - METAL OPEN-TOP DRAINAGE STRUCTURES
August 26, 1996
DESCRIPTION
649.01 Work. This work consists of installing metal open-top drainage structures in
accordance with these specifications and in reasonable close conformity with the lines and
grades SHOWN ON THE DRAWINGS. This work includes all excavation, bedding, and
backfill required to complete the work. Installation also includes furnishing the anchor pins,
and any necessary cutting and welding of sections.
MATERIALS
649.02. Drainage structure material shall be a "flying W" configuration guardrail as furnished
by the government.
649.03 Anchor pins. Anchor pins shall be galvanized or zinc-coated steel and may be round
or rectangular cross-section. Anchor pins shall be a minimum 16 mm diameter x 460 mm
long, with a 30 mm diameter head and used with a 40 mm diameter washer.
CONSTRUCTION
649.04 Installation. Install the metal open-top drainage structures at the locations and to the
lines and grades SHOWN ON THE DRAWINGS and staked on the ground. Cut and splice
guardrail as needed to provide continuous drainage structures at each installation. Weld in
accordance with Section 555 and as SHOWN ON THE DRAWINGS.
649.05 Excavation. Excavation shall be in accordance with the requirements of Section
206A.
649.06 Bedding. Provide bedding for a firm foundation of uniform density throughout the
length of the structure.
649.07 Anchoring. Place anchor pins as SHOWN ON THE DRAWINGS.
anchoring devices may be used if approved in writing by the Engineer.
Alternative
649.08 Backfilling. Do not place or backfill metal open-top drainage structures until the
structure, excavation, and bedding have been approved by the Engineer.
Backfill the excavated area around the structure with suitable material, not exceeding 40 mm
in diameter, after bedding is prepared and the drainage structure is placed. The moisture
content of the backfill material will be suitable for effective compaction. The backfill material
will be compacted with a mechanical tamper until visual displacement ceases.
R6/SPS 649 METAL OPEN-TOP DRAINAGE 8/26/96
1
MEASUREMENT
649.09 Method. The method of measurement will be DESIGNATED in the SCHEDULE OF
ITEMS and measured in accordance with Section 106.
PAYMENT
649.10 Basis. The accepted quantities will be paid for in accordance with Section 106 at the
contract unit price for each pay item shown in the SCHEDULE OF ITEMS.
Pay Item
Pay Unit
649(01)
Install Metal Open-Top Drainage Structure . . . . . . . . . meters
649(02)
Install Metal Open-Top Drainage Structure . . . . . . . . . EA.
R6/SPS 649 METAL OPEN-TOP DRAINAGE 8/26/96
2