Today’s girders are much longer and heavier than those that have been used in the past. This poses challenges to transportation agencies in handling, transporting, and erecting the girders, as under their own weight they can buckle laterally and fail. Traditionally, analysis of this potential behavior has ignored torsional deformations because doing so greatly simplifies the calculations. However, although traditional models have so far proved adequate, today’s longer, heavier girders are challenging their assumptions. And with those girders, the potential consequences of ignoring torsional deformation could prove to be not only costly in terms of time and money but also unsafe. This project is seeking to improve the fundamental characterization of girder instability by developing new models that include torsional deformation and consider a broad range of material properties and concrete weights. Models will be developed to analyze both the lateral stability of uncracked girders and the role of cracking in reducing girder stiffness and thus increasing instability. The researchers will assist WSDOT in implementing the findings by providing the lateral stability criteria necessary to develop a set of new girder shapes that will take advantage of the materials that allow the use of longer spans.
Principal Investigators:
John Stanton, Civil and Environmental Engineering, UW
Richard Wiebe, Civil and Environmental Engineering, UW
Sponsor: WSDOT
WSDOT Technical Monitor: Geoff Swett
WSDOT Project Manager: Mustafa Mohamedali
Scheduled completion: March 2024