Determining the presence of scour around bridge foundations using vehicle-induced vibrations

Prendergast, Luke J.; Hester, David; Gavin, Kenneth

Abstract

Bridge scour is the number one cause of failure in bridges located over waterways. Scour leads to rapid losses in foundation stiffness and can cause sudden collapse. Previous research on bridge health monitoring has used changes in natural frequency to identify damage in bridge beams. The possibility of using a similar approach to identifying scour is investigated in this paper. To assess if this approach is feasible, it is necessary to establish how scour affects the natural frequency of a bridge, and if it is possible to measure changes in frequency using the bridge dynamic response to a passing vehicle. To address these questions, a novel vehicle–bridge–soil interaction (VBSI) model was developed. By carrying out a modal study in this model, it is shown that for a wide range of possible soil states, there is a clear reduction in the natural frequency of the first mode of the bridge with scour. Moreover, it is shown that the response signals on the bridge from vehicular loading are sufficient to allow these changes in frequency to be detected.

• Journal Article Type: Article
• Acceptance Date: Mar 4, 2016
• Online Publication Date: Apr 15, 2016
• Publication Date: 2016-10
• Deposit Date: Aug 21, 2018
• Publicly Available Date: Aug 22, 2018
• Journal: Journal of Bridge Engineering
• Print ISSN: 1084-0702
• Electronic ISSN: 1943-5592
• Publisher: American Society of Civil Engineers
• Peer Reviewed: Peer Reviewed
• Volume: 21
• Issue: 10
• Article Number: 04016065
• DOI: https://doi.org/10.1061/%28asce%29be.1943-5592.0000931
• Keywords: Scour; Vibrations; Frequency; Soil stiffness; Bridges; Structural health monitoring (SHM)
• Public URL: https://nottingham-repository.worktribe.com/output/1042174
• Publisher URL: https://ascelibrary.org/doi/10.1061/%28ASCE%29BE.1943-5592.0000931
• Additional Information: © 2016 American Society of Civil Engineers; ; This material may be downloaded for personal use only. Any other use requires prior permission of the American Society of Civil Engineers. This material may be found at https://ascelibrary.org/doi/10.1061/%28ASCE%29BE.1943-5592.0000931.