284 ALASKA 2020 DIVISION 600 –MISCELLANEOUS CONSTRUCTION METAL FLUME DOWNDRAI NS
601-1.01 DESCRIPTION. Furnish and install tapered inlet assemblies, metal flume downdrains,
and anchor assemblies, at the locations shown on the Plans.
601-2.01 MATERIALS. Fabricate tapered inlets and flume downdrains using any one of the base
metals listed in AASHTO M 36 or AASHTO M 196. Use a minimum sheet thickness of 0.060 inches. Use steel nuts and bolts, galvanized acc ording to AASHTO M 232.
601-3.01 CONSTRUCTIO N REQUIREMENTS. Fabricate downdrains according to the details
and dimensions shown on the Plans. Weld bulkheads and flume pieces to the inlet assembly to form watertight connections. Do not use dissimilar metal at any one installation. Anchor assemblies shown on the Plans may be used with an aluminum installation if the anchor assemblies are electrically insulated. Connect flume downdrain sections together and to the inlet assembly using galvanized bolts as show n on the Plans.
601-4.01 METHOD OF M EASUREMENT. See Section 109, measured along the invert from the
lower end of the inlet assembly, not including flume stub, to the lower end of the flume.
601-5.01 BASIS OF PA YMENT. The contract price includes the inlet, anchor assemblies,
miscellaneous hardware, and excavation for the installation. Payment will be made under: PAY ITEM Item Number Item Description Unit 601.0001.____ Metal Flume Downdrain LF 285 ALASKA 2020 SECTION 602 STRUCTURAL PLATE PIP E
602-1.01 DESCRIPTION . Construct galvanized corrugated steel plate or aluminum alloy plate
pipes, at the locations shown on the Plans.
602-2.01 MATERIALS. Use materials that conform to the following:
Pipe Subsection 707- 2.04 Bedding and backfill Subsection 204- 2.01
602-3.01 CON STRUCTION REQUIREMENTS. Lay field -assembled plate pipes in conformance
to the lines and grades approved by the Engineer. Excavation, grading, and backfill must conform to Subsection 204- 3.01. Repair damage to the zinc coating according to AASHTO M 36. Pre-shape bedding material to fit the lower portion of the pipe. Pre- shape to a depth of one- tenth of the pipe height and wide enough to permit compaction under the haunches. Strutting is not permitted. When elongated pipes are specified, form the plate sections at the factory so that the pipe’s vertical dimension is increased by 5 percent of the specified diameter. Provide the Engineer with a copy of the manufacturer's recommendations and instructions and comply with them.
602-4.01 METHOD OF M EASUREMENT. See Section 109, measured along the invert of each
pipe of the type and size specified.
602-5.01 BASIS OF PA YMENT. Structure excavation, bedding, and backfill for structural plate
pipe is paid for under Section 204. Payment will be made under: PAY ITEM Item Number Item Description Unit 602.0001.____ Structural Plate Pipe ___Diameter, ___Gauge LF 602.0002.____ Structural Plate Pipe -Arch ___Span, ___Rise, ___Gauge LF 602.0003.____ Structural Plate Arch, ___Span, ___Rise, ___Gauge LF