TY - JOUR
T1 - Bridge scour identification and field application based on ambient vibration measurements of superstructures
AU - Xiong, Wen
AU - Cai, C. S.
AU - Kong, Bo
AU - Zhang, Xuefeng
AU - Tang, Pingbo
N1 - Funding Information:
Acknowledgments: The financial support for this work from the Natural Science Foundation of Jiangsu Province of China (Project No. BK20161417), Fundamental Research Funds for the Central Universities (2242016R30023), and Highway Science and Technology Project of Zhejiang Province of China (2018H10) is gratefully acknowledged. The opinions and statements do not necessarily represent those of the sponsors.
Funding Information:
Funding: This research was funded by the Natural Science Foundation of Jiangsu Province of China (grant number BK20161417), Fundamental Research Funds for the Central Universities (grant number 2242016R30023), and Highway Science and Technology Project of Zhejiang Province of China (grant number 2018H10).
Publisher Copyright:
© 2019 by the authors.
PY - 2019/5/1
Y1 - 2019/5/1
N2 - A scour identification method was developed based on the ambient vibration measurements of superstructures. The Hangzhou Bay Bridge, a cable-stayed bridge with high scour potential, was selected to illustrate the application of this method. Firstly, two ambient vibration measurements were conducted in 2013 and 2016 by installing the acceleration sensors on the girders and pylon. By modal analysis, the natural frequencies of the superstructures were calculated with respect to different mode shapes. Then, by tracing the change of dynamic features between two measurements in 2013 and 2016, the discrepancies of the support boundary conditions, i.e., at the foundation of the Hangzhou Bay Bridge, were detected, which, in turn, qualitatively identified the existence of bridge foundation scour. Secondly, an FE model of the bridge considering soil-pile interaction was established to further quantify the scour depth in two steps. (1) The stiffness of the soil springs representing the support boundary of the bridge was initially identified by the model updating method. In this step, the principle for a successful identification is to make the simulation results best fit the measured natural frequencies of those modes insensitive to the scour. (2) Then, using the updated FE model, the scour depth was identified by updating the depth of supporting soils. In this step, the principle of model updating is to make the simulation results best fit the measured natural frequency changes of those modes sensitive to the scour. Finally, a comparison to the underwater terrain map of the Hangzhou Bay Bridge was carried out to verify the accuracy of the predicted scour depth. Based on the study in this paper, it shows that the proposed method for identifying bridge scour based on the ambient vibration measurements of superstructures is effective and convenient. It is feasible to quickly assess scour conditions for a large number of bridges without underwater devices and operations.
AB - A scour identification method was developed based on the ambient vibration measurements of superstructures. The Hangzhou Bay Bridge, a cable-stayed bridge with high scour potential, was selected to illustrate the application of this method. Firstly, two ambient vibration measurements were conducted in 2013 and 2016 by installing the acceleration sensors on the girders and pylon. By modal analysis, the natural frequencies of the superstructures were calculated with respect to different mode shapes. Then, by tracing the change of dynamic features between two measurements in 2013 and 2016, the discrepancies of the support boundary conditions, i.e., at the foundation of the Hangzhou Bay Bridge, were detected, which, in turn, qualitatively identified the existence of bridge foundation scour. Secondly, an FE model of the bridge considering soil-pile interaction was established to further quantify the scour depth in two steps. (1) The stiffness of the soil springs representing the support boundary of the bridge was initially identified by the model updating method. In this step, the principle for a successful identification is to make the simulation results best fit the measured natural frequencies of those modes insensitive to the scour. (2) Then, using the updated FE model, the scour depth was identified by updating the depth of supporting soils. In this step, the principle of model updating is to make the simulation results best fit the measured natural frequency changes of those modes sensitive to the scour. Finally, a comparison to the underwater terrain map of the Hangzhou Bay Bridge was carried out to verify the accuracy of the predicted scour depth. Based on the study in this paper, it shows that the proposed method for identifying bridge scour based on the ambient vibration measurements of superstructures is effective and convenient. It is feasible to quickly assess scour conditions for a large number of bridges without underwater devices and operations.
KW - Ambient vibration
KW - Bridge scour
KW - Cable-stayed bridge
KW - Field application
KW - Identification
KW - Mode shape
KW - Natural frequency
KW - Superstructure
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U2 - 10.3390/jmse7050121
DO - 10.3390/jmse7050121
M3 - Article
AN - SCOPUS:85066442628
SN - 2077-1312
VL - 7
JO - Journal of Marine Science and Engineering
JF - Journal of Marine Science and Engineering
IS - 5
M1 - 121
ER -