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On methods for extending a single footfall trace into a continuous force curve for floor vibration serviceability analysis

  • Chen, Jun (State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University) ;
  • Peng, Yixin (State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University) ;
  • Ye, Ting (State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University)
  • Received : 2012.02.14
  • Accepted : 2013.03.30
  • Published : 2013.04.25

Abstract

An experimentally measured single footfall trace (SFT) from a walking subject needs to be extended into a continuous force curve, which can then be used as load for floor vibration serviceability assessment, or on which further analysis like discrete Fourier transform can be conducted. This paper investigates the accuracy, applicability and parametrical sensitivity of four extension methods, Methods I to IV, which extends the SFT into a continuous time history by the walking step rate, stride time, double support proportion and the double support time, respectively. Performance of the four methods was assessed by comparing their results with the experimentally obtained reference footfall traces in the time and frequency domain, and by comparing the vibrational response of a concrete slab subjected to the extended traces to that of reference traces. The effect of the extension parameter on each method was also explored through parametrical analysis. This study finds that, in general, Method I and II perform better than Method III and IV, and all of the four methods are sensitive to their extension parameter. When reliable information of walking rate or gait period is available in the test, Methods I or II is a better choice. Otherwise, Method III, with the suggested extension parameter of double support time proportion, is recommended.

Keywords

Acknowledgement

Supported by : National Science Foundation of China, Shanghai Natural Science Foundation

References

  1. British Standards Institution (BSI) (1987), "BS 6841: Guide to measurement and evaluation of human exposure to whole-body mechanical vibration and repeated shock", London.
  2. Chen, J., Jiang, S.Y., Wang, L., Peng, Y.X. and Cheng, Y.W. (2011), "Experiments on Human-induced excitation using 3D motion capture and analysis", Proceeding of the Third Asia-Pacific Young Researchers and Graduates Symposium, Taipei, Taiwan, China, March.
  3. Chen, J., Peng, Y.X. and Ye, T. (2012), "Loads generated by human walking: experiments and numerical modelling", Proceedings of the Twelfth International Symposium on Structural Engineering, Wuhan, China, November.
  4. Dallard, P., Fitzpatrick, T. and Flint, A. et al. (2001), "London Millennium Bridge: pedestrian-induced lateral vibration", J. Bridge Eng., ASCE, 6(6), 412-417. https://doi.org/10.1061/(ASCE)1084-0702(2001)6:6(412)
  5. Ebrahimpour, A., Hamam, A., Sack, R.L. and Patten, W.N. (1996), "Measuring and modeling dynamic loads imposed by moving crowds", J. Struct. Eng., ASCE, 122(2), 1468-1474. https://doi.org/10.1061/(ASCE)0733-9445(1996)122:12(1468)
  6. Ebrahimpour, A. and Sack, R.L. (2005), "A review of vibration serviceability criteria for floor structures", Comput. Struct., 83(28-30), 2488-2494. https://doi.org/10.1016/j.compstruc.2005.03.023
  7. Ellingwood, B. and Tallin, A. (1984), "Structural serviceability: floor vibrations", J. Struct. Eng., ASCE, 110(2), 401-418. https://doi.org/10.1061/(ASCE)0733-9445(1984)110:2(401)
  8. Galbraith, F.W. and Barton, M.V. (1970), "Ground loading from footsteps", J. Acoust. Soc. AM, 48(5), 1288-1292. https://doi.org/10.1121/1.1912271
  9. Han, S.W. and Lee, M. et al. (2009), "Acceleration thresholds of vertical floor vibrations according to human perception levels in Korea", Adv. Struct. Eng., 12(4), 595-607. https://doi.org/10.1260/136943309789508537
  10. Harper, F.C. and Warlow, W.J. et al. (1961), The forces applied to the floor by the foot in walking, HM Stationery Off.
  11. International Organization for Standardization (ISO) (2003), "Evaluation of human exposure to whole-body vibration - Part 2: Continuous and shock induced vibration in buildings (1 to 80 Hz)", ISO 2631-2, Switzerland.
  12. Kerr, S.C. and Bishop, N. (2001), "Human induced loading on flexible staircases", Engineering Structures, 23(1), 37-45. https://doi.org/10.1016/S0141-0296(00)00020-1
  13. Kirtley, C. (2006), Clinical gait analysis: theory and practice, Churchill Livingstone.
  14. Liu, J.J. and Xiao, C.Z. (2008), "Vertical response analysis of floor under jumping and walking load", Building Structures, 38(2), 108-110. (in Chinese)
  15. Murray, T.M., Allen, D.E. and Ungar, E.E. (1997), "Floor vibration due to human activity", AISC design guide series, No 11, AISC, Chicago.
  16. Nguyen, T.H., Gad, E.F., Wilson, J.L. and Haritos, N. (2012), "Improving a current method for predicting walking-induced floor vibration", Steel Compos. Struct., 13(2), 139-155. https://doi.org/10.12989/scs.2012.13.2.139
  17. Ohlsson, S. (1982), "Floor vibration and human discomfort", Doctoral Thesis at Chalmers University of Technology, Division of Steel and Timber Structures.
  18. Pavic, A. and Reynolds, P. (2002), "Vibration serviceability of long-span concrete building floors. Part 1: review of background information", Shock and Vibration Digest, 34(3), 191-211.
  19. Racic, V. and Pavic, A. et al. (2009), "Experimental identification and analytical modelling of human walking forces: Literature review", J. Sound Vib., 326(1-2), 1-49. https://doi.org/10.1016/j.jsv.2009.04.020
  20. Rainer, J.H. and Pernica, G. et al. (1988), "Dynamic loading and response of footbridges", Can. J. Civil Eng., 15(1), 66-71. https://doi.org/10.1139/l88-007
  21. Song, Z.G. and Jin, W.L. (2004), "Peak acceleration response spectrum of long span floor vibration by pedestrian excitation", J. Building Structures, 25(2), 57-63. (in Chinese)
  22. Strogatz, S.H. and Abrams, D.M. et al. (2005), "Theoretical mechanics: crowd synchrony on the Millennium Bridge", Nature, 438(7064), 43-44. https://doi.org/10.1038/438043a
  23. Wang, L., Wang, H.Q., Peng, Y.X., Chen, B. and Chen, J. (2011), "Novel techniques for human-induced loading experiment and data processing", Proceeding of the International Symposium on Innovation & Sustainability of Structures in Civil Engineering, Xiamen, China, October.
  24. Willford, M.R. and Young, P. (2006), Design guide for footfall induced vibration of structure. A tool for designers to engineer the footfall vibration characteristics of buildings or bridges, The Concrete Centre, UK.

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