Of the nearly 600,000 bridges listed in the Federal Highway Administration's (FHWA) National Bridge Inventory, close to 1,000 bridges are movable bridges. The design and installation of structural, mechanical and electrical components provide significant challenges for designers, contractors and owners in any movable bridge project. 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. The second edition of the Manual was published in 2007, with yearly Interim Revisions from 2008 to 2012.   

 

Based on the input from movable bridge owners, designers and industry representatives, the current specifications need further updating to incorporate the Load and Resistance Factor Design (LRFD) method, which follows a reliability-based design methodology and to reflect advances in electrical drives and controls, mechanical systems, and traffic/marine safety systems.

 

 

The objectives of this research are to:

 

 (1) Develop a stand-alone synthesis of the various types of electrical controls and drives, and mechanical systems currently being used in movable bridges;

 

 (2) Identify the areas of the AASHTO LRFD Movable Bridge Design Specifications that require modification or addition to incorporate the LRFD method and to reflect the advances in structural materials and design, electrical drives and controls, mechanical systems, and traffic/marine safety systems; and

 

 (3) Propose recommendations for future research needs.

 

PRODUCTS AVAILABILITY

Agency final report was submitted to AASHTO SCOBS, T-8 Moveable Bridg. (NCHRP Staff: W. Dekelbab)