Examination of Level of Analysis Accuracy for Curved I-Girder Bridges through Comparisons to Field Data
Publication: Journal of Bridge Engineering
Volume 11, Issue 2
Abstract
To evaluate the accuracy of different levels of analysis used to predict horizontally curved steel I-girder bridge response, a field test was performed on a three-span structure. Collected strain data were reduced to determine girder vertical and bottom flange lateral bending moments. Experimental moments were compared to numerical moments obtained from three commonly employed levels of analysis. Level 1 analysis includes two manual calculation methods: a line girder analysis method described in the AASHTO Guide Specification for Horizontally Curved Highway Bridges, and the V-load method. Grillage models represent Level 2 and were created using three commercially available computer programs: SAP2000, MDX, and DESCUS. Level 3 consists of three-dimensional (3D) finite element models created using SAP2000 and the BSDI 3D system. Responses obtained from each level are compared and discussed for a single radial cross section of the structure, and the compared results involve truck loads and placement schemes that do not represent those used for bridge design. The field test and numerical data presented are used solely to determine the accuracy of each level of analysis for predicting structure response to a specific live load at a specific cross section. Results showed that Level 2 and Level 3 analyses predict girder vertical bending moment distributions more accurately than Level 1 analyses throughout the tested cross section. The comparisons indicate that Level 3 girder vertical bending moment distributions offered no appreciable increase in accuracy over Level 2 analyses. The study also indicates that both Level 1 and Level 3 analyses provide bottom flange lateral bending moment distributions that do not correlate well with field test results for the studied bridge cross section.
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Acknowledgments
The writers wish to thank the following organizations for their support of this study: the Federal Highway Administration, PennDOT District 2-0, Norfolk Southern, and the Pennsylvania Transportation Institute.
References
AASHTO. (1993). Guide specifications for horizontally curved highway bridges, AASHTO, Washington, D.C.
AASHTO. (2003). Guide specifications for horizontally curved highway bridges, AASHTO, Washington, D.C.
Beal, D. B., and Kissane, R. J. (1971a). First Interim Report on Research Project 42-1, New York State Department of Transportation, Engineering Research and Development Bureau Albany, New York.
Beal, D. B., and Kissane, R. J. (1971b). Second Interim Report on Research Project 42-1, New York State Department of Transportation, Engineering Research and Development Bureau, Albany, New York.
Beal, D. B., and Kissane, R. J. (1972). Third Interim Report on Research Project 42-1, New York State Department of Transportation, Engineering Research and Development Bureau, Albany, New York.
Bridge Software Development International, Ltd. (BSDI). (2000). Bridge Software Development International product scope, BSDI, Coopersburg, Pa.
DESCUS Software, (2002). “Design and Analysis of Curved I-Girder Bridge System User Manual,” Opti-mate, Inc.
Galambos, T. V., Ajar, J. F., Leon, R. T., Huang, W., Pulver, B. E., and Rudie, B. J. (1996). “Stresses in steel curved girder bridges.” Minnesota Department of Transportation Rep. No. MN/RC-96/28, Minneapolis.
Hajjar, J. F., and Boyer, T. A. (1997). “Live load stresses in steel curved girder bridges.” Progress Report on Task 1 for Minnesota Department of Transportation Project 74708, December, Minnesota Department of Transportation, Minneapolis.
Linzell, D. G. (1999). “Studies of a full-scale horizontally curved steel I-girder bridge system under self-weight,” Thesis, Georgia Institute of Technology, July 1999.
McElwain, B. A., and Laman, J. A. (2000). “Experimental verification of horizontally curved I-girder bridge behavior.” J. Bridge Eng., 5(4), 284–292.
MDX. (2000). Curved and straight steel bridge design and rating user manual, MDX Software, Inc., Columbia, Mo.
Modjeski and Masters, Inc. (1989). Review of computer programs for the analysis of girder bridges, Pennsylvania Department of Transportation, Harrisburg, Pa.
National Steel Bridge Alliance (NSBA). (1996). “Chapter 12: V-load analysis—An approximate procedure, simplified and extended, for determining moments and shear in designing horizontally curved open-frame highway bridges.” Highway structures design handbook, Vol. 1, Ch. 12, NSBA, Chicago.
Nevling, D. L. (2003). “Evaluation of level of analysis methodologies for horizontally curved I-girder bridges through comparison with measured response of an in-service structure,” MS thesis, Pennsylvania State Univ., University Park, Pa.
SAP2000. (2000). SAP2000 nonlinear version 6.0 user manual, Computers and Structures, Inc., Berkeley, Calif.
White, D. W., Zureick, A. H., Phoawanich, N., and Jung, S. (2001). Development of unified equations for design of curved and straight steel bridge I-girders, Prepared for American Iron and Steel Institute Transportation and Infrastructure Committee, Professional Services, Inc., and Federal Highway Administration, Georgia Institute of Technology, Atlanta.
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© 2006 ASCE.
History
Received: Jan 30, 2004
Accepted: Mar 15, 2005
Published online: Mar 1, 2006
Published in print: Mar 2006
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