Comparisons of the Computed and Measured Behavior of Curved Steel I-Girders during Lifting
Publication: Journal of Structural Engineering
Volume 138, Issue 1
Abstract
The stability of I-girders during erection can be difficult to assess because of the limited presence of bracing and uncertainty in the support conditions of the girders. The behavior of curved girders during the early stages of construction is complicated because the curved geometry can lead to significant torsion. This paper highlights results from a research study that included both field monitoring and parametric finite-element investigations. Curved I-shaped girders were instrumented and monitored during lifting to provide data to validate finite-element models. Both rotational displacements and stress were measured during the lifting process. In this paper, the writers compare data collected from field tests with results computed from detailed finite-element simulations. A prismatic and a nonprismatic girder (with two different cross sections) were considered in the investigation. The I-girders experienced both rigid body rotation and cross-sectional twist. Additionally, the torsional warping stresses were observed to be of the same order of magnitude as the strong-axis bending stresses. However, it should be noted that the total stresses were well below yielding. The fact that the stresses are low during lifting should not be confused with a noncritical stage in the safety of the girders. Although the applied stresses are low, the stresses necessary to buckle the girder or to cause large deformations are also relatively low because usually no bracing exists and limited restraint is provided to the girders during lifting. The finite-element models were able to capture the measured behavior accurately, providing insight into appropriate assumptions and critical features for modeling curved I-girders during lifting.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The authors would like to thank the Texas Department of Transportation for their technical and financial support of this project. Additionally, the authors would like to extend our thanks to Hirschfeld Industries LP for the use of both facilities and equipment necessary in completion of the field experiment. The authors would like to extend special thanks to Jeremiah Fasl for his assistance with the instrumentation and data acquisition during the field tests.
References
AASHTO. (2007). AASHTO LRFD Bridge Design Specifications, 4th Ed., Washington, DC.
ANSYS 11.0 [Computer software]. (2007). ANSYS, Inc., Canonsburg, PA.
Farris, J. F. (2008). “Behavior of horizontally curved steel I-girders during construction.” M.S. thesis, Univ. of Texas at Austin, Austin, TX.
Galambos, T. V., Hajjar, J. F., Huang, W., Pulver, B. E., Leon, R. T., and Rudie, B. J. (2000). “Comparison of measured and computed stresses in a steel curved girder bridge.” J. Bridge Eng., 5(3), 191–199.
Mast, R. F. (1989). “Lateral stability of long prestressed concrete beams—Part 1.” PCI J., 34(1), 34–53.
Maxwell, T., and Yednak, C. (2005). “Crews retrieve worker’s body.” Chicago Tribune, Aug. 21.
National Transportation Safety Board. (2006). Highway Accident Brief, Accident No. HWY-04-MH-023, Washington, DC.
Schuh, A. C. (2008). “Behavior of horizontally curved steel I-girders during lifting.” M.S. thesis, Univ. of Texas at Austin, Austin, TX.
Information & Authors
Information
Published In
Copyright
© 2012 American Society of Civil Engineers.
History
Received: Sep 6, 2010
Accepted: Apr 18, 2011
Published online: Apr 20, 2011
Published in print: Jan 1, 2012
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.