Vibration serviceability considerations in footbridge design.

Abstract

Modern footbridges are becoming more and more flexible as they are constructed lighter and more slender than ever before. This has led to a vibration serviceability issue with many footbridges, as they can become ‘lively’ by pedestrians simply walking across them. Numerous codes of practice and guidelines are available to the structural engineer, in terms of footbridge design, all with their limitations in terms of overcoming this serviceability problem. This paper carries out a critical review of these guidelines and codes of practice, and their approach to addressing the issue of vibration serviceability. Moreover, the paper investigates human loading and the parameters that affect such loading, in both a qualitative and quantitative fashion. Furthermore, an explanation is provided on how an understanding of human loading and the parameters that affect such loading can be used to predict and address vibration serviceability problems on footbridges. Finally, walking trials conducted by the authors in which pedestrian loading at normal pacing velocities was examined are briefly described; along with a note on current and future studies to be undertaken.