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Shock and Vibration
Volume 12 (2005), Issue 5, Pages 333-347
http://dx.doi.org/10.1155/2005/857247

Vibration Excitation and Control of a Pedestrian Walkway by Individuals and Crowds

James Mark William Brownjohn1 and Tao Neng Fu2

1School of Engineering, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK
2Civil Engineering and Building Department, Singapore Polytechnic, 500 Dover Road, 139651, Singapore

Received 24 September 2004; Revised 18 January 2005

Copyright © 2005 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

As part of a continuing study on effects of humans on loading and dynamic response of footbridges, a steel frame walkway has been the subject of studies on the effects of multiple pedestrians with respect to loading and response mitigation. Following finite element modeling and experimental modal analysis to identify the low frequency vibration modes likely to be excited by normal walking, the variation of response with pedestrian density and of system damping and natural frequency with occupancy by stationary pedestrians were both studied. The potentially mitigating effect of stationary occupants is still not well understood and the study included direct measurement of damping forces and absorbed energy using a force plate. The various tests showed that energy dissipation measured directly was consistent with the observed change in damping, that vertical and lateral response both varied approximately with square root of number of pedestrians, and that the simple model of a human as a single mass-spring-damper system may need to be refined to fit observed changes in modal parameters with a crowd of humans present. Modal parameter changes with moving pedestrians were small compared to those with stationary pedestrians indicating that within limits, modal parameters for the empty structure could be used in analysis.