Vortex‐induced vibration measurement of a long‐span suspension bridge through noncontact sensing strategies. (28th June 2021)

• Record Type: Journal Article
• Authors: Zhang, Jian; Zhou, Liming; Tian, Yongding; Yu, Shanshan; Zhao, Wenju; Cheng, Yuyao
• Is Part Of: Computer-aided civil and infrastructure engineering. Volume 37:Number 12(2022)
• Page Start: 1617
• Page End: 1633
• Publication Date: 2021-06-28
• Subjects: Civil engineering -- Data processing -- Periodicals; Computer-aided engineering -- Periodicals; 624.0285
• DOI: 10.1111/mice.12712
• Languages: English
• ISSNs: 1093-9687

Abstract

Abstract: Long‐span bridges are susceptible to vortex‐induced vibration (VIV), which affects the serviceability and safety of bridges when the vibration amplitude is too large and lasts for a long time. Traditional contact‐type sensing technologies (i.e., accelerometers and linear variable differential transformer) are inconvenient and dangerous to be installed on long‐span bridges for monitoring VIV events. To address this limitation, this article focuses on the VIV measurement of a long‐span suspension bridge through noncontact sensing strategies. The contribution of this article lies in (1) noncontact sensing technologies including microwave radar, optical camera and video equipment were employed to measure multiple‐point displacements of the studied bridge under VIV events; (2) dynamic properties of the bridge (i.e., natural frequency, damping ratio, mode shapes) and characteristics of the VIV event (i.e., single‐mode vibration and dominant vibration mode switch) were identified by analyzing monitoring data; (3) an early warning framework for VIV event of long‐span suspension bridges was proposed based on monitored dynamic responses and wind fields; specifically, two indicators, the dominant vibration frequency and the similarity between bridge shape and vibration mode shape, were proposed to identify the VIV event, and then the root mean square (RMS) of measured response was further calculated to determine whether there is a need to trigger the warning system or not. The proposed noncontact VIV measurement strategy has the advantage of rapid measurement of vibration magnitude, rapid identification of dynamic properties of the studied bridge and characteristics of the VIV event, which are helpful for the government and bridge owners to make decisions on vibration mitigation measures and to avoid safety issues.