Direct Measurement of Dynamics in Road Bridges Using a Bridge Weigh-In-Motion System

Eugene J. OBrien, Arturo González, Jason Dowling, Aleš Žnidarič


A method is presented of measuring a bridge’s characteristic allowance for dynamic interaction in the form of Assessment Dynamic Ratio. Using a Bridge Weigh-in-Motion system, measurements were taken at a bridge in Slovenia over 58 days. From the total observed traffic population, 5-axle trucks were extracted and studied. The Bridge Weigh-in-Motion system inferred the static weights of the trucks, giving each measured event’s dynamic increment of load. Theoretical simulations were carried out using a 3-dimensional vehicle model coupled with a bridge plate model, simulating a traffic population similar to the population measured at the site. These theoretical simulations varied those properties of the 5-axle fleet that influence the dynamic response; simulating multiple sets of total (dynamic + static) responses for a single measured static strain response. Extrapolating the results of these theoretical simulations to a 50-year Assessment Dynamic Ratio gives similar results to those obtained by extrapolating the data measured using the Bridge Weigh-in-Motion system. A study of the effect of Bridge Weigh-in-Motion system errors on the predictions of Assessment Dynamic Ratio is conducted, identifying a trend in the Bridge Weigh-in-Motion calculations of maximum static response. The result of this bias is in turn quantified in the context of predicting characteristic maximum total load effect.


bridge; dynamics; Assessment Dynamic Ratio; soft load testing; Vehicle Bridge Interaction; Weigh-in-Motion (WIM)

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Bhattacharya, B.; Li, D.; Chajes, M. 2005. Load and Resistance Factor Rating Using Site Specific Data, Transportation Research Record: Journal of the Transportation Research Board, CD 11-S, Transportation Research Board of the National Academies, Washington, D.C. 143–151.

Castillo, E. 1988. Extreme Value Theory in Engineering. Academic Press, NewYork. 389 p. ISBN 978-0-12-163475-9.

Chatterjee, S. 1991. The Design of Modern Steel Bridges. Oxford BSP Professional Books, Oxford. 224 p. ISBN 0632055111

Cremona, C. 2001. Optimal Extrapolation of Traffic Load Effects, Structural Safety 23(1): 31–46.

Crespo-Minguillon, C.; Casas, J. R. 1997. A Comprehensive Traffic Load Model for Bridge Safety Checking, Structural Safety 19(4): 339–359.

Dawe, P. 2003. Traffic Loading on Highway Bridges. Thomas Telford, London. 196 p. ISBN: 9780727732415.

Fu, T. T.; Cebon, D. 2002. Analysis of a Truck Suspension Database, International Journal of Heavy Vehicle Systems 9(4): 281–297.

Harris, N. K.; OBrien, E. J.; González, A. 2007. Reduction of Bridge Dynamic Amplification through Adjustment of Vehicle Suspension Damping, Journal of Sound and Vibration 302(3): 471–485.

Huang, D.; Wang, T.; Shahawy, M. 1993. Impact Studies of Multigirder Concrete Bridges, Journal of Structural Engineering 119(8): 2387–2402.

Kim, C. W.; Kawatani, M.; Kim, K. B. 2005. Three-Dimensional Dynamic Analysis for Bridge–Vehicle Interaction with Roadway Roughness, Computers and Structures 83(19–20): 1627–1645.

Kirkegaard, P. H.; Nielsen, S. R. K.; Enevoldsen, I. 1997. Heavy Vehicles on Minor Highway Bridges – Dynamic Modelling of Vehicles and Bridges. Report in Dept of Building Technology and Structural Engineering, Aalborg University, ISSN1395-7953R9721. 37 p.

Law, S. S.; Zhu, X. Q. 2005. Bridge Dynamic Responses Due to Road Surface Roughness and Braking of Vehicle, Journal of Sound and Vibration 282(3–5): 805–830.

Moses, F. 1979. Weigh-in-Motion System Using Instrumented Bridges, ASCE Journal of Transportation Engineering 105(3): 233–249.

Nowak, A. S.; Eom, J.; Ferrand, D. 2003. Verification of Girder Distribution Factors for Continuous Steel Girder Ridges. Michigan Dept of Transportation, Contract No. 95-0242.

OBrien, E. J.; Cantero, D.; Enright, B.; González, A. 2010. Characteristic Dynamic Increment for Extreme Traffic Loading Events on Short and Medium Span Highway Bridges, Engineering Structures 32(12): 3287–3835.

OBrien, E. J.; Rattigan, P. H.; González, A.; Dowling, J.; Žnidarič, A. 2009. Characteristic Dynamic Traffic Load Effects in Bridges, Engineering Structures 31(7): 1607–1612.

OBrien, E. J.; Quilligan, M.; Karoumi, R. 2006. Calculating an Influence Line from Direct Measurements, Proceedings of the Institution Civil Engineers, Bridge Engineering 159(1): 31–34.

Rowley, C. W.; OBrien, E. J.; González, A.; Žnidarič, A. 2009. Experimental Testing of a Moving Force Identification Bridge Weigh-in-Motion Algorithm, Experimental Mechanics 49(5): 743–746.

Rowley, C.; González, A.; OBrien, E. J.; Žnidarič, A. 2008. Comparison of Conventional and Regularised Bridge Weigh-in-Motion Algorithms, in International Conference on Heavy Vehicles Paris 2008, Weigh-in-Motion (ICWIM5). Ed. by Jacob, B.; OBrien, E. J.; OConnor, A.; Bouteldja, M. Paris, France, 271–283.

Tierney, O. F.; OBrien, E. J.; Peters, R. J. 1996. The Accuracy of Australian and European Culvert Weigh-in-Motion Systems, in Proc. of National Traffic Data Acquisition Conference, vol. 2. Ed. by Knoebel, G. Alliance for Transportation Research, 647–656.

Wilson, S. P.; Harris, N. K.; OBrien, E. J. 2006. The Use of Bayesian Statistics to Predict Patterns of Spatial Repeatability, Transportation Research 14(5): 303–315.

Wong, J. Y. 1993. Theory of Ground Vehicles. Wiley, NewYork. 592 p. ISBN 0470170387.

Zhang, Q-L.; Vrouwenvelder, A.; Wardenier, J. 2000. Dynamic Amplification Factors and EUDL of Bridges under Random Traffic Flows, Journal of Engineering Structures 23(6): 663–672.

Žnidarič, A.; Lavrič, I.; Kalin, J. 2010. Latest Practical Development in the WIM Technology, in Proc. of the 5th International Conference on Bridge Maintenance, Safety and Management. Ed. by Frangopol, D. M. July 11–15, 2010, Philadelphia, Pennsylvania, 993–1000.

DOI: 10.3846/bjrbe.2013.34


1. Determination of load equivalency factors by statistical analysis of weigh-in-motion data
Zoltán Soós, Csaba Tóth, Dávid Bóka
The Baltic Journal of Road and Bridge Engineering  vol: 11  issue: 4  first page: 251  year: 2016  
doi: 10.3846/bjrbe.2016.31


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