Quantification of pedestrian's comfort level and dynamic properties of footbridge vibration based on in-situ measurement

Peng Feng, Fei Fei Jin, Lie Ping Ye, Songye Zhu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

7 Citations (Scopus)

Abstract

Although natural frequency and acceleration response are recognized as two main indices in footbridge design with respect to pedestrian's comfort level, supporting in-situ measurement data are actually limited. In view of this, twenty one in-service footbridges in Beijing are investigated in this study. The vibration acceleration time history of each bridge was recorded; meanwhile, randomly selected pedestrians were surveyed regarding their comfort feeling via questionnaire. A total of 1053 valid questionnaire were collected. The dynamic responses of each footbridge were also measured under different pedestrian loading cases. The analyses of in-situ measurement data reveal the correlation between maximal acceleration and RMS acceleration, the correlation between dynamic response produced by single pedestrian and that by crowds, as well as the correlation between footbridge span length and natural vibration frequency. Combined with the information from questionnaire survey, two pedestrian's comfort level indices, termed felt fraction and comfortable fraction, are quantitatively defined, and their relations to natural frequency and maximal acceleration of footbridges are examined. It is demonstrated that the two factors have weak correlation to the first modal frequency in vertical direction, but have strong correlation to the maximal acceleration. The regression analyses of the felt fraction-maximal acceleration curve and the comfortable fraction-maximal acceleration curve provide a quantitative expression for pedestrians comfort level on footbridges and a mapping between pedestrian's comfort level and acceleration. These will be the basis of performance-based design for footbridge vibration in future.
Original languageEnglish
Pages (from-to)545-553
Number of pages9
JournalZhendong Gongcheng Xuebao/Journal of Vibration Engineering
Volume26
Issue number4
Publication statusPublished - 29 Oct 2013

Keywords

  • Comfort level index
  • Felt fraction
  • Foot bridge
  • Maximal acceleration
  • Natural frequency

ASJC Scopus subject areas

  • Mechanical Engineering
  • Mechanics of Materials
  • Acoustics and Ultrasonics
  • Civil and Structural Engineering
  • Aerospace Engineering

Cite this