Proposed Revisions to AASHTO-LRFD Bridge Design Specifications for Orthotropic Steel Deck Bridges

Abstract

The orthotropic steel deck bridge is a structural system that has the potential to provide an extended service life and standardized modular design as compared to more conventional bridge construction. This paper summarizes proposed changes to the fifth edition of the AASHTO LRFD Bridge Design Specifications related to orthotropic deck bridges. The current version of AASHTO-LRFD contains provisions that provide limited guidance to complete the fatigue design. Contained within these proposed changes is a new framework for design verification, which may be based on different levels of design or physical testing. Criteria related to loads, load factors, limit states including fatigue in particular, resistance, and analysis requirements are covered in detail. Designs made according to these new provisions can be expected to perform very well and meet the design service life as per AASHTO-LRFD.