Detection of Anomalous Sequences in Crack Data of a Bridge Monitoring

Long term bridge monitoring Application to the Bruneseau Bridge

Revue française de génie civil ◽

10.3166/rfgc.5.469-482 ◽

2001 ◽

Vol 5 (4) ◽

pp. 469-482

Author(s):

Jean Carracilli

Keyword(s):

Bridge Monitoring ◽

Monitoring Application

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Modal frequencies of bridges from GNSS (GPS) monitoring data: Experimental, statistical evidence

Bridge Structures ◽

10.3233/brs-210184 ◽

2021 ◽

Vol 17 (1-2) ◽

pp. 3-14

Author(s):

Stathis C. Stiros ◽

F. Moschas ◽

P. Triantafyllidis

Keyword(s):

Signal To Noise Ratio ◽

Vertical Axis ◽

Bridge Monitoring ◽

Low Snr ◽

True Value ◽

Gps Satellites ◽

Wide Range ◽

Spectral Peaks ◽

Monitoring Survey ◽

True Frequency

GNSS technology (known especially for GPS satellites) for measurement of deflections has proved very efficient and useful in bridge structural monitoring, even for short stiff bridges, especially after the advent of 100 Hz GNSS sensors. Mode computation from dynamic deflections has been proposed as one of the applications of this technology. Apart from formal modal analyses with GNSS input, and from spectral analysis of controlled free attenuating oscillations, it has been argued that simple spectra of deflections can define more than one modal frequencies. To test this scenario, we analyzed 21 controlled excitation events from a certain bridge monitoring survey, focusing on lateral and vertical deflections, recorded both by GNSS and an accelerometer. These events contain a transient and a following oscillation, and they are preceded and followed by intervals of quiescence and ambient vibrations. Spectra for each event, for the lateral and the vertical axis of the bridge, and for and each instrument (GNSS, accelerometer) were computed, normalized to their maximum value, and printed one over the other, in order to produce a single composite spectrum for each of the four sets. In these four sets, there was also marked the true value of modal frequency, derived from free attenuating oscillations. It was found that for high SNR (signal-to-noise ratio) deflections, spectral peaks in both acceleration and displacement spectra differ by up to 0.3 Hz from the true value. For low SNR, defections spectra do not match the true frequency, but acceleration spectra provide a low-precision estimate of the true frequency. This is because various excitation effects (traffic, wind etc.) contribute with numerous peaks in a wide range of frequencies. Reliable estimates of modal frequencies can hence be derived from deflections spectra only if excitation frequencies (mostly traffic and wind) can be filtered along with most measurement noise, on the basis of additional data.

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Assessing the potential value of bridge monitoring systems

Proceedings of the Institution of Civil Engineers - Bridge Engineering ◽

10.1680/jbren.15.00016 ◽

2016 ◽

Vol 169 (2) ◽

pp. 126-138 ◽

Cited By ~ 9

Author(s):

Paul J. Vardanega ◽

Graham T. Webb ◽

Paul R. A. Fidler ◽

Campbell R. Middleton

Keyword(s):

Monitoring Systems ◽

Bridge Monitoring ◽

Potential Value

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Research and Design on Monitoring System of Simple Bridge Based on Virtual Instrument Technology

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.490-495.2624 ◽

2012 ◽

Vol 490-495 ◽

pp. 2624-2627

Author(s):

Hua Wen Zheng ◽

Liu Chang ◽

Chuan Hui Wu ◽

Yu Liang

Keyword(s):

Monitoring System ◽

Virtual Instrument ◽

Analysis Data ◽

System Structure ◽

Time Data ◽

Bridge Monitoring ◽

Instrument Technology ◽

Software And Hardware ◽

Bridge Monitoring System ◽

Research And Design

Design of a monitoring system based on virtual instrument technology for a simple bridge. This paper discusses the bridge monitoring system structure, software and hardware. The system can realize functions such as data acquisition, real-time data display, online analysis, offline analysis, data management and so on. Therefore, the monitoring system can be applied to a variety of bridges. The presented monitoring system has an important guidance meaning and practical value for bridge monitoring.

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