NCHRP 20-07
Proposed Research Needs Statement

AASHTO Subcommittee on Bridges and Structures
Gregg C. Fredrick, Wyoming
April, 2013

TITLE
Review and Summarize update needs of the AASHTO LRFD Movable Highway Bridge Design Specifications

BACKGROUND / NEEDS STATEMENT
Of the nearly 600,000 bridges listed in the Federal Highway Administration's (FHWA) National Bridge Inventory, close to 1,000 fall into the category of movable bridges.

The design and installation of structural, mechanical and electrical components provide significant challenges for designers, contractors and owners in any movable bridge rehabilitation or replacement project. Two sources of information help engineers and owners design these components. Those are the AASHTO Movable Bridge Inspection, Evaluation and Maintenance Manual first published in 1998 and currently under study to be updated and the FHWA Bridge Inspector’s Manual for Movable Bridges, published in 1977.

The primary design guide for movable bridge design and construction is the AASHTO LRFD Movable Highway Bridge Design Specifications. This Manual was first published in 2000 with 2002 Interim Revisions.

Based on input to the AASHTO Technical Panel(T-8) for Movable Bridges from owners, designers and industry representatives, the current specifications need further updating to meet the changes precipitated by LRFD. Updating design and load factor requirements for mechanical components such as span locks has been an item of recent discussion at T-8 and is the object of current research.

This proposed research would review the current specifications and recommend items that need to be updated to comply with LRFD as well as proposing items for updating the to reflect changes and technological advances impacting electrical and mechanical drives and systems.

The results of this research would then serve as the basis for a further contract to actually update the specifications.

RESEARCH OBJECTIVE
Review current AASHTO LRFD Movable Bridge Design Specifications and propose items for further updating to meet LRFD requirements and that reflect advances in electrical drives and controls and mechanical systems.

WORK TASKS
Tasks anticipated in this project include the following:

  • Review current movable bridge specifications
  • List of items/calculations that do not meet LRFD standards
  • List of electrical and mechanical systems that do not reflect current industry standards and should be updated to reflect state-of-the-art designs

FUNDING REQUESTED AND TIME REQUIRED
It is estimated that this research will take 12 months to complete and will require $100,000.

CONTACT PERSONS:

Paul B. Fossier, Jr., PE, M.ASCE

Chairman, AASHTO SCOBS T-8 Technical Committee for Movable Bridges

Administrator, Bridge and Structural Design

Louisiana Department of Transportation & Development

225-379-1302 (office)

Mr. Earl Dubin, P.E.

Secretary: AASHTO SCOBS T-8 Technical Committee for Movable Bridges

FHWA; Structural Engineer

919-747-7012

Email: