Section 571 - Prefabricated Bridges.pdf

Section 571—Prefabricated Bridges

Description

571.01 Design, fabricate, deliver, and install a prefabricated, modular bridge superstructure, or transport and install a Government-furnished prefabricated, modular superstructure and components. Construct the length, width, including curbs and railings, horizontal and vertical alignment, materials, appearance, and design requirements as shown on the plans.

Unless components are furnished by the Government, furnish prefabricated, modular bridge superstructure components complete and in place, including deck and railing, when required, to form a bridge superstructure capable of supporting traffic as soon as construction of approaches is complete. Include all incidental materials required to provide a completed structure ready for use.

Materials

571.02 Requirements. Furnish materials that meet the requirements specified in the following sections:

Bridge Railing 556

Structural Metal 717

Prestressed Concrete 553

Reinforcing Steel 554

Steel Structures 555

Structural Concrete 552

Timber Structures 557

Material for Timber Structures 716

Concrete compressive strength, structural steel tensile strength, finish, designation, timber species, grade, treatment, and other material specifications shall be as shown on the plans. If material specifications are not in the contract documents, take them from the manufacturer’s drawings, and have them approved by the CO prior to fabrication.

Construction Requirements

571.03 General. Fabricate the prefabricated steel bridge in a fabrication plant that is currently certified for “Major Steel Bridge (CBR)”, under the American Institute of

Steel Construction (AISC) Quality Certification Program. Fabricate “fracture-critical” elements in accordance with the AASHTO “Guide Specifications for Fracture Critical Non-Redundant Steel Bridge members.”

571.04 Design Requirements. Design in accordance with the AASHTO “LRFD Bridge Design Specifications”, Fifth Edition - 2010, using the AASHTO HL-93 design vehicle, including impact, unless otherwise shown on the plans. For pedestrian bridges, design in accordance with the AASHTO “LRFD Guide Specifications for the Design of Pedestrian Bridges”, December 2009.

571.05 Drawings and Calculations. When furnishing a prefabricated bridge superstructure, submit for approval four copies of the design drawings, calculations, shop drawings, and any manufacturer’s installation special handling instructions. The shop drawings shall list all design loads, design criteria, welding procedures, list of materials and specifications, weight summary, support reactions, connection details, and shall detail each component in the bridge assembly. Include plan, elevation, and section views of the prefabricated bridge superstructure. The shop drawings shall be prepared by the AISC certified shop that is fabricating the bridge superstructure. All documents shall be signed and sealed by a registered professional engineer who is currently licensed in the State where the bridge will be located as shown on the plans. Submit all documents not less than 21 days in advance of the start of the fabrication.

571.06 Performance. Notify the CO at least 14 days before delivery and/or installation of the prefabricated bridge.

If the prefabricated superstructure is not installed immediately upon delivery to the project site, provide appropriate equipment and labor to unload and stack, support, and store all material at the delivery point. Support and stack all components to prevent damage. Furnish and install blocking to support all components at least 12 inches above the ground.

Furnish all tools, devices, special equipment, and material needed for installation in well-marked watertight containers suitable for long-term, outdoor storage.

571.07 Contractor-Furnished Prefabricated Bridge Superstructure. Furnish the following items for approval prior to delivery of the bridge component:

(a) Supplier or inspection agency certification of wood species and grade of all timber and a conformance certificate for all sawn and glued laminated members.

(b) Certification by an approved inspection and testing agency of wood treatment, listing method of treatment, type of preservative, retention, and penetration. Supplier certification is permitted if each piece is stamped or branded with a legible American Wood Preservers Bureau quality mark.

(c) Certification of structural steel, fasteners, and hardware.

(d) Certification of galvanizing process used.

(e) Steel fabricator certification that steel fabrication and quality control meet the requirements of the AISC Code of Standard Practice; and that all welding meets the requirements of ANSI/AASHTO/AWS D 1.5 Bridge Welding Code.

(f) A complete list of all bridge components, hardware, and fasteners.

(g) Complete instructions and drawings. Provide drawings that are black line, of reproducible quality, on ANSI sheet size D (24 inches by 36 inches). Furnish the same information in an approved electronic format.

Mark each major component of the bridge superstructure with the same permanent serial number in a location that is clearly visible, both when stacked in storage and erected at the site.

Assemble bridge superstructure prior to delivery to assure proper fit-up of all components. Notify the CO 2 weeks before shop assembly.

571.08 Government-Furnished Prefabricated Bridge Superstructure. For Government-furnished prefabricated bridge units, transport all material from the storage site(s) to the bridge site, and install the superstructure complete and in place, including connection of all girders, diaphragms, railings, panels, transoms, and other elements.

Upon taking possession of the Government-furnished units at the storage site, assume liability for damage resulting from handling, transporting, or erecting the units in place, until final acceptance of the project.

571.09 Acceptance. Material will be evaluated under Section 106.03. Furnish a production certification with shipment of the prefabricated bridge.

Construction of the prefabricated bridge will be evaluated under Subsections 106.02 and 106.04.

Measurement

571.10 Measure the Section 571 items listed in the bid schedule according to Subsection 109.02.

Payment

571.11 The accepted quantities, measured as provided in Subsection 109.02 and above, will be paid at the contract price per unit of measurement for the Section 571 pay items listed in the bid schedule. Payment will be full compensation for the work prescribed in this Section. See Subsection 109.05.