November 2, 2021 - 12:00pm to 1:00pm

Two new AASHTO Guide Specifications were released at the end of 2018. They offer the analytical framework needed to revisit the way we evaluate redundancy in steel bridges considering system-level and member-level redundancy for new or existing bridges.

For the last four decades, the steel bridge industry has become accustomed to determining redundancy through engineering judgment married to a single approach, namely load path redundancy (referring to the number of girder lines). Publication of these Guide Specifications enables designers and owners to design outside the box that we put ourselves in 40 years ago. In addition, The Guide Specifications also include a methodology to establish an inspection interval for a special inspection of internally redundant members (IRMs) that is of sufficient depth to reliably detect a severed component. This is a major departure from the current calendar-based approach to setting inspection intervals and is a first step toward developing an integrated fracture control plan by AASHTO.  

This presentation will gather perspectives from the aviation industry to discuss the development of these new AASHTO Guide Specifications in the context of historical AASHTO fracture control approaches. It will explore the research behind the new guide specifications, suggested implementation, and help the audience further understand the value of integrating the fracture control plan in this way while revisiting concepts in redundancy of steel bridges.  

Learning Objectives

  • Identify the two factors of risk
  • Describe the effectiveness of the AASHTO fracture control plan over the last 40+ years
  • Identify two modes of redundancy for steel bridges, other than load-path redundancy.

This presentation will not be recorded for future viewing

1 CE Hour


This is a virtual event on Zoom. Please register before 10:00 am on Monday, 11/1/21 to ensure you receive access to the presentation.

Members - $25
Non-Members - $50

About the Speaker

Jason B. Lloyd, PhD, PE
Bridge Steel Specialist
National Steel Bridge Alliance

Dr. Jason Lloyd is the Bridge Steel Specialist, Western Market, for the National Steel Bridge Alliance, a division of the American Institute of Steel Construction. He represents the steel bridge industry on matters of steel bridge fabrication and construction. Jason's role with NSBA is to provide technical assistance, tools, and resources for steel bridges to bridge owners, designers, fabricators, university programs, and technical committees. Prior to joining the NSBA, Jason spent seven years as a research engineer at Purdue University's Bowen Lab and S-BRITE Center where he specialized in full-scale fatigue and fracture research, field testing of steel structures, and repair and retrofit of steel bridges. He earned his MS and PhD from Purdue  University.  Jason currently serves on several technical committees, research technical advisory groups, and technical collaborations, is a licensed professional engineer in the state of Indiana, and a former US Navy Seabee.  



Denise Soehrman ( Alfred Benesch & Co. )
Johann Aakre ( Michael Baker International )
Cory Chamberlain ( WHKS & Co. )
Victor Sanchez ( FARNSWORTH GROUP )
Patrick Hannemann ( Hanson Professional Services Inc. )
Christopher Stine ( AECOM )
Jorge Medina ( Burns and McDonnell )
Donald Meinheit ( Wiss, Janney, Elstner Associates, Inc. )
Dennis Penepacker ( None )
Ronald Neumann ( Retired )
Maysaloon Abugrain ( AISC )