Vertical footbridge vibrations: details regarding and experimental validation of the response spectrum methodology

Einar Thór Ingólfsson, Christos Georgakis, Martin Nymann Svendsen

Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review


In this paper, details regarding and the experimental validation of the “response spectrum” methodology for the determination of vertical footbridge response are presented. The methodology is inspired by the well-established response spectrum approach used in the majority of the world’s current seismic design codes of practice. A basic outline of the methodology is given, followed by a detailed examination of the bridge-specific parameters that are applied to adjust the response obtained from a universal reference design spectrum. The bridge-specific parameters take into account key variations in footbridge configuration such as bridge length, damping, mode shapes and modal mass. Furthermore, the effect of changes in the mean flow rate of a random crowd is examined as is the concept pf a “crowd return period”. The detailed results from a set of full-scale experiments, conducted on an 80m RC footbridge, are presented. An accurate representation of the random crowd loading during the experiments is created through video-footage and used to theoretically predict the vertical bridge response following the response spectrum methodology. The predictions verify the effectiveness of the methodology, as bridge response is overestimated by only 7%.
Original languageEnglish
Title of host publicationThird International Conference FOOTBRIDGE 2008 : Footbridges for urban renewal
Publication date2008
Publication statusPublished - 2008
EventThird International Conference: Footbridges for urban renewal - Porto, Portugal
Duration: 2 Jul 20084 Jul 2008
Conference number: 3


ConferenceThird International Conference: Footbridges for urban renewal


  • Footbridge
  • experimental validation
  • crowd load
  • vertical vibration
  • response spectrum

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