Equivalent Wheel Load Approach for Slender Cable-Stayed Bridge Fatigue Assessment under Traffic and Wind: Feasibility Study
Publication: Journal of Bridge Engineering
Volume 12, Issue 6
Abstract
In the current AASHTO LRFD specifications, the fatigue design considers only one design truck per bridge with 15% dynamic allowance. While this empirical approach may be practical for regular short and medium span bridges, it may not be rational for long-span bridges (e.g., span length or ) that may carry many heavy trucks simultaneously. Some existent studies suggested that fatigue may not control the design for many small and medium bridges. However, little research on the fatigue performance of long-span bridges subjected to both wind and traffic has been reported and if fatigue could become a dominant issue for such a long-span bridge design is still not clear. Regardless if the current fatigue design specifications are sufficient or not, a real understanding of the traffic effects on bridge performance including fatigue is desirable since the one truck per bridge for fatigue design does not represent the actual traffic condition. As the first step toward the study of fatigue performance of long-span cable-stayed bridges under both busy traffic and wind, the equivalent dynamic wheel load approach is proposed in the current study to simplify the analysis procedure. Based on full interaction analyses of a single-vehicle–bridge–wind system, the dynamic wheel load of the vehicle acting on the bridge can be obtained for a given vehicle type, wind, and driving condition. As a result, the dimension of the coupled equations is independent of the number of vehicles, through which the analyses can be significantly simplified. Such simplification is the key step toward the future fatigue analysis of long-span bridges under a combined action of wind and actual traffic conditions.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The research is partially supported by Colorado State University through its faculty startup funding for the first writer and NSF Grant No. NSFCMS-0301696 for the second writer. Opinions, findings, and conclusions expressed are those of the writers, and do not necessarily present the views of the sponsors.
References
AASHTO. (2002). Standard specification for highway bridges, Washington, D.C.
AASHTO. (2004). LRFD bridge design specifications, Washington, D.C.
Blejwas, T. E., Feng, C. C., and Ayre, R. S. (1979). “Dynamic interaction of moving vehicles and structures.” J. Sound Vib., 67, 513–521.
Cai, C. S., and Chen, S. R. (2004a). “Framework of vehicle–bridge–wind dynamic analysis.” J. Wind. Eng. Ind. Aerodyn., 92(7–8), 579–607.
Cai, C. S., and Chen, S. R. (2004b). “Wind vibration mitigation of long-span bridges in hurricanes.” J. Sound Vib., 274, 421–432.
Calcada, R., Cunha, A., and Delgado, R. (2005). “Analysis of traffic-induced vibrations in a cable-stayed bridge. Part II: Numerical modeling and stochastic simulation.” J. Bridge Eng., 10(4), 386–397.
Chen, S. R. (2004). “Dynamic performance of bridges and vehicles under strong wind.” Ph.D. dissertation, Louisiana State Univ., Baton Rouge, La.
Chen, S. R., and Cai, C. S. (2004). “Accident assessment of vehicles on long-span bridges in windy environments.” J. Wind. Eng. Ind. Aerodyn., 92(12), 991–1024.
Chen, S. R., and Cai, C. S. (2006). “Unified approach to predict the dynamic performance of transportation system considering wind effects.” Struct. Eng. Mech., 23(3), 279–292.
Coleman, S. A., and Baker, C. J. (1990). “High-sided road vehicle in cross winds.” J. Wind. Eng. Ind. Aerodyn., 36, 1383–1392.
Gu, M., Xu, Y. L., Chen, L. Z., and Xiang, H. F. (1999). “Fatigue life estimation of steel girder of Yangpu cable-stayed bridge due to buffeting.” J. Wind. Eng. Ind. Aerodyn., 80(3), 383–400.
Guo, W. H., and Xu, Y. L. (2001). “Fully computerized approach to study cable-stayed bridge-vehicle interaction.” J. Sound Vib., 248(4), 745–761.
Huang, D. (2005). “Dynamic and impact behavior of half-through arch bridges.” J. Bridge Eng., 10(2), 133–141.
Huang, D., Wang, T.-L., and Shahawy, M. (1995). “Vibration of thin-walled box-girder bridges excited by vehicles.” J. Struct. Eng., 121(9), 1330–1337.
Jain, A., Jones, N. P., and Scanlan, R. H. (1996). “Coupled flutter and buffeting analysis of long-span bridges.” J. Struct. Eng., 122(7), 716–725.
Pourzeynali, S., and Datta, T. K. (2005). “Reliability analysis of suspension bridges against fatigue failure from the gusting of wind.” J. Bridge Eng., 10(3), 262–271.
Timoshenko, S., Young, D. H., and Weaver, W. (1974). Vibration problems in engineering, 4th Ed., Wiley, New York.
Zaman, M., Taheri, M. R., and Khanna, A. (1996). “Dynamic response of cable-stayed bridges to moving vehicles using the structural impedence method.” Appl. Math. Model., 20(12), 877–889.
Information & Authors
Information
Published In
Copyright
© 2007 ASCE.
History
Received: Apr 6, 2006
Accepted: Jan 2, 2007
Published online: Nov 1, 2007
Published in print: Nov 2007
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.