Multi-sensor measurement of dynamic deflections and structural health monitoring of flexible and stiff bridges

Stiros, S.; Psimoulis, P.; Moschas, F.; Saltogianni, V.; Tsantopoulos, E.; Triantafyllidis, P.

Abstract

We investigated the response of bridges of different types to controlled and to wind and traffic-induced excitations; the emphasis was on deflections,derived from recordings of geodetic sensors and accelerometers (output-only analysis). Our focus was to push the limits of the existing experimental techniques, in order to cover not only flexible, but also stiff structures, and to present independently validated results. Our study focused on a 700m long, thin-deck cable-stayed bridge, a stiff steel pedestrian bridge, a historic composite (masonry/steel) train bridge and a 30m long, gradually decaying, currently swaying pedestrian timber bridge. Our basic strategy was first to develop data measurement and processing techniques using controlled (supervised learning) experiments, and then, (1) use collocated, redundant and distributed geodetic sensors (GPS/GNSS and Robotic Total Stations, RTS), as well as accelerometers, in order to record bridge excitations, especially con-trolled excitations leading to free attenuating oscillations;(2) develop techniques to denoise recordings of various sensors based on structural/logical constraints and sensor fusion, compensating for the weaknesses inherent in each type of sensor), validate results and avoid pitfalls;(3) monitor the episodic and gradual decay of a pedestrian bridge, through repeated surveys under similar loading and environmental conditions and using similar instrumentation.The output of our studies is to confirm the potential of modern sensors to measure, under certain conditions, reliable mm-level dynamic deflections even of stiff structures (3-6Hz dominant frequencies) and to provide firm constraints for structural analysis, including evidence for changes of first modal frequencies produced by structural decay, even to identify dynamic effects such as foundations response to dynamic loading.

Citation

Stiros, S., Psimoulis, P., Moschas, F., Saltogianni, V., Tsantopoulos, E., & Triantafyllidis, P. (2019). Multi-sensor measurement of dynamic deflections and structural health monitoring of flexible and stiff bridges. Bridge Structures, 15(1-2), 43-51. https://doi.org/10.3233/brs-190152

• Journal Article Type: Article
• Acceptance Date: Aug 14, 2019
• Online Publication Date: Aug 14, 2019
• Publication Date: Aug 14, 2019
• Deposit Date: Sep 20, 2019
• Publicly Available Date: Aug 15, 2020
• Journal: Bridge Structures
• Print ISSN: 1573-2487
• Electronic ISSN: 1744-8999
• Publisher: Taylor & Francis Open
• Peer Reviewed: Peer Reviewed
• Volume: 15
• Issue: 1-2
• Pages: 43-51
• DOI: https://doi.org/10.3233/brs-190152
• Keywords: Building and Construction
• Public URL: https://nottingham-repository.worktribe.com/output/2641087
• Publisher URL: https://content.iospress.com/articles/bridge-structures/brs190152