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Effects of Pedestrian Excitation on Two Short-Span FRP Footbridges in Delft

  • Stana Živanović
  • Justin Russell
  • Marko Pavlović
  • Xiaojun Wei
  • J. Toby Mottram
Conference paper
Part of the Conference Proceedings of the Society for Experimental Mechanics Series book series (CPSEMS)

Abstract

Reported in this paper is an evaluation of the vibration behaviour of two footbridges in The Netherlands having main spans of about 15 m. Short-span footbridges over canals and rivers are embedded in the landscape of Delft and elsewhere. Increasingly, these bridges are made of Fibre-Reinforced Polymer (FRP) composites, utilising the high-strength and light-weight nature of the material, and taking advantage of fast installation and low maintenance costs. Due to low mass, these FRP bridges might be sensitive to dynamic excitation by human actions. The two footbridges investigated in this paper have the main bearing structure which consists of either two or four longitudinal beams made of vacuum infused FRPs with foam cores connected by an FRP deck. Modal testing revealed that fundamental vertical natural frequency of the two structures at 4.8 and 6.1 Hz is in the range typical of similar structures made of concrete and steel, whilst the corresponding damping ratio for the wider, slightly cambered, bridge was exceptionally high at 7.9%. The vibration response to dynamic force by people walking was typically up to 1 m/s2. While both of these light-weight structures performed satisfactorily under the regular pedestrian loading, the higher frequency – higher damping structure represents an example of successful control of pedestrian-induced vibrations by means of longitudinal restraints at the end supports and slightly curved shape of the main structure.

Keywords

FRP composites Short-span footbridges Modal properties Vibration Walking 

Notes

Acknowledgements

This research work was supported by the UK Engineering and Physical Sciences Research Council [grant number EP/M021505/1: Characterising Dynamic Performance of Fibre Reinforced Polymer Structures for Resilience and Sustainability]. The authors would like to thank the Delft Municipality for logistic support during testing as well as companies MOCS and FWD for sharing the bridge design data.

References

  1. 1.
    Smiths, J.: Fiber-reinforced polymer bridge design in the Netherlands: architectural challenges toward innovative, sustainable, and durable bridges. Engineering. 2, 518–527 (2016)CrossRefGoogle Scholar
  2. 2.
    McConnell, K.G., Varoto, P.S.: Vibration Testing: Theory and Practice, 2nd edn. Wiley, Hoboken (2008)Google Scholar
  3. 3.
    ME’scope, version 16.0.5.19: Vibrant Technology (2016)Google Scholar
  4. 4.
    Fladung, B.: Windows used for impact testing. In: Proceeding of IMAC-XV. Orlando (1997)Google Scholar
  5. 5.
    Sétra (Service d’Etudes Techniques des Routes et Autoroutes): Footbridges, assessment of vibrational behaviour of Footbridges under pedestrian loading. Technical Guide, Paris (2006)Google Scholar
  6. 6.
    Tilly, G.P., Cullinngton, D.W., Eyre, R.: Dynamic Behaviour of Footbridges, IABSE Surveys S-26/84, IABSE Periodica, No. 2/84, 1984, pp. 13–24 (1984)Google Scholar
  7. 7.
    Pavic, A., Willford, M.: Vibration Serviceability of Posttensioned Concrete Floors. Post-Tensioned Concrete Floors Design Handbook, 2nd edn. Appendix G, Technical Report 43, pp. 99–107. Concrete Society, Slough (2005)Google Scholar
  8. 8.
    Živanović, S., Pavic, A.: Probabilistic modelling of walking excitation for building floors. J. Perform. Constr. Facil. 23(3), 132–143 (2009)CrossRefGoogle Scholar

Copyright information

© The Society for Experimental Mechanics, Inc. 2019

Authors and Affiliations

  • Stana Živanović
    • 1
  • Justin Russell
    • 1
  • Marko Pavlović
    • 2
  • Xiaojun Wei
    • 1
  • J. Toby Mottram
    • 1
  1. 1.School of EngineeringUniversity of WarwickCoventryUK
  2. 2.Department of Structural EngineeringTU DelftDelftThe Netherlands

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