Steel Bridge Analysis Guide Revised

A revision of Guidelines for Steel Girder Bridge Analysis, G13.1 (2nd Edition) is now available following final approval by AASHTO. The guide has been updated to reflect recent advances in the state of knowledge of steel girder bridge analysis, primarily associated with the completion of NCHRP Research Project 12-79 and the publication of NCHRP Report 725, Guidelines for Analysis Methods and Construction Engineering of Curved and Skewed Steel Girder Bridges.

These updates provide quantitative-based guidance on appropriate levels of analysis for steel girder bridges, discuss recommended improvements to the modeling of I-girder torsional stiffness and truss-type cross frame stiffness to increase the accuracy of 2D analysis methods, and present a new method for estimating I-girder flange lateral bending stresses in straight skewed bridges using 2D analysis. Also included are clarifications on the prediction of deflections and load rating analysis, as well recent recommendations addressing the impact of connection stiffness on cross-frame stiffness, and recent guidelines on global second-order amplification of structural response and narrow system stability analysis.

The work was developed by the AASHTO/NSBA Steel Bridge Collaboration Task Group 13, comprised of contributing members from the analysis software, design consulting, DOT, fabricator, detailer, erector, and academic communities. The Task Group made it their goal to identify appropriate analysis methods to provide sufficient refinement while avoiding the potential traps that can be associated with “over-analysis,” as well as guidance on how to use those methods properly. G13.1’s revisions continue the Collaboration’s mission of distributing standardized best practices of benefit to owners, designers, and contractors.

This document is available for download through the NSBA website on the AASHTO/NSBA Steel Bridge Collaboration page under Standards, as well as the AASHTO website.