The National Academies

NCHRP 20-07/Task 355 [Final]

Guidelines for Reliable Fit-Up of Steel I-Girder Bridges
[ NCHRP 20-07 (Research for AASHTO Standing Committee on Highways) ]

  Project Data
Funds: $100,000
Research Agency: Georgia Institute of Technology
Principal Investigator: Dr. Donald W. White
Effective Date: 5/20/2014
Completion Date: 8/31/2015

Steel I-girder bridges are much-used options for utilization on complex curved and/or skewed alignments. However, current practices for detailing the fit-up of cross-frames combined with challenging attributes of the framing arrangements and erection procedures often result in problems during and after construction. For example:
  • Girders and cross frames that are difficult to fit-up during erection and require unplanned contractor operations such as force fitting of connections, field drilling or field welding;
  • Erected girders with webs that are significantly out of plumb which render their performance uncertain without further evaluation;
  •  Locked in stresses (in cross frames and/or girders) that were not appropriately accounted for in design; and
  • Bearings rotated beyond tolerable design limits.
In certain instances, these problems have resulted in construction delays, unnecessary rework, cost and schedule overruns, and disputes and litigation. These problems can be avoided by developing a better understanding of the ways in which the framing arrangements, cross-frame detailing practices and erection procedures affect fit-up during steel erection.
The objective of this research is to propose design and detailing guidelines to ensure reliable fit-up of curved and/or skewed steel I-girder bridges. These guidelines will provide a clear understanding of the implications of various framing arrangements, fit-up conditions for detailing, and erection procedures on the resulting constructed geometry, ease of fit-up during erection, and locked-in stresses in the cross-frames and/or girders.

Agency's final report was submitted to AASHTO SCOBS, T-14 Structural Steel Design. Please be aware that the file is too large and will take time for downloading it.
(NCHRP Staff: W. Dekelbab)

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