Perceptibility of Vibrations by Pedestrians

Abstract

<p>The serviceability criteria for pedestrian structures against vibrations in many recent Standards and guidelines are not based on a consistent probabilistic concept considering the large natural scatter in human responses. While earlier recommendations are the results of on engineering judgement based on a few experiments, the fairly large and still deterministic limiting values in actual design recommendations seem to have no sound scientific justification. The actual study discusses the different serviceability effects as listed in ISO 10137, and points out that beside the question to comfort further and more severe aspects have to be taken into account like fear, interference with activities and possibility of injury. Furthermore, the paper summarizes the known features in the random scatter of perception and evaluation of vibrations for passive persons. The basic random scatter in regard to vibration perception for walking persons is analysed based on field experiments with soldiers marching in step. A marker is dropped as soon as the person feels the vibration. The position of the marker is used to identify the individual times when vibrations have been percieved during the crossing process. The experienced vibration cycle before dropping the marker contains the required threshold information. The perception threshold values of 42 persons are used to identify a theoretical model for the probability distribution. Further tests give first rough estimates for the threshold levels in regard to interference and distortion effects.</p>