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Structural health monitoring (SHM) techniques are used to assess the behavior of structures during or after construction. The high cost of sensors is the main reason for the limited use of the SHM techniques. The present study investigates the dynamic behavior (dynamic acceleration, semi-static displacement, frequency and damping ratio) of highway steel plate girder bridges using strain measurements. The double filtration and polynomial prediction methods are used to estimate the dynamic behavior of the bridge using real-time strain measurements. To verify the accuracy of the developed method, the field monitoring measurements of the WonHyo bridge is used. The bridge behavior under different truck speeds and weights is observed and evaluated. The displacement and acceleration measurements are used to examine the results of the proposed method. The results of this study demonstrate that the strain measurements can be used to obtain an accurate semi-static displacement and dominant frequency content of the bridge. The accuracy of the developed model for the semi-static and dynamic behaviors is 99% and 69%, respectively. [ABSTRACT FROM AUTHOR]

This paper presents the recent development in Structural Health Monitoring (SHM) applications for monitoring the dynamic behavior of structures using the Global Positioning Systems (GPS) technique. GPS monitoring systems for real-time kinematic (RTK), precise point positioning (PPP) and the sampling frequency development of GPS measurements are summarized for time series analysis. Recent proposed time series GPS monitoring systems, errors sources and mitigation, as well as system analysis and identification, are presented and discussed. [ABSTRACT FROM AUTHOR]

Recently, trains' velocities in Korea increased more than the speed used in the design of some bridges. Accordingly, this paper demonstrates the evaluation of a railway bridge due to high-speed trains' movement. A nondestructive monitoring system is used to assess the bridge performance under train speeds of 290, 360, 400 and 406 km/h. This system is comprised of a wireless short-term acceleration system and strain monitoring sensors attached to the bridge girder. The results of the analytical methods in time and frequency domains are presented. The following conclusions are obtained: the cross-correlation models for accelerations and strain measurements are effective to predict the performance of the bridge; the static behavior is increased with train speed developments; and the vibration, torsion, fatigue and frequency contents analyses of the bridge show that the bridge is safe under applied trains' speeds. [ABSTRACT FROM AUTHOR]

The Global Positioning System (GPS) is recently used widely in structures and other applications. Notwithstanding, the GPS accuracy still suffers from the errors afflicting the measurements, particularly the short-period displacement of structural components. Previously, the multi filter method is utilized to remove the displacement errors. This paper aims at using a novel application for the neural network prediction models to improve the GPS monitoring time series data. Four prediction models for the learning algorithms are applied and used with neural network solutions: back-propagation, Cascade-forward back-propagation, adaptive filter and extended Kalman filter, to estimate which model can be recommended. The noise simulation and bridge's short-period GPS of the monitoring displacement component of one Hz sampling frequency are used to validate the four models and the previous method. The results show that the Adaptive neural networks filter is suggested for de-noising the observations, specifically for the GPS displacement components of structures. Also, this model is expected to have significant influence on the design of structures in the low frequency responses and measurements' contents. [ABSTRACT FROM AUTHOR]

Deformation and expansion joint movement of bridges are among the problems that widely exist in bridge engineering practice. Therefore, it is very important to monitor deformation of bridges and to timely process and analyze the measured data to ensure their safety. Mansoura Bridge, located at El-Mansoura City in Egypt, is selected to demonstrate the utilization of bridge deck deformation monitoring data to analyze and evaluate its safety based on global positioning system (GPS) measurements. The wavelet principal component analysis (WPCA) and spectrum methods are used to establish the time and frequency domain of bridge deformation and analyze the behavior and movement of the bridge under working traffic loads. The following conclusions are obtained in this study: (1) the WPCA can be used to eliminate the GPS observation errors; (2) the three-dimension spectrum gives much richer information for dynamic response; and (3) the deformation and expansion joint movement of Mansoura Bridge are safe under current loads. [ABSTRACT FROM AUTHOR]

Highlights: [•] RTK-GPS measurements are used to monitor and model the movement of bridge deck. [•] Moving average filter increased the accuracy by 15%. [•] Multi filter of short-period can reveal the dynamic displacement of the bridge deck movement. [•] The movement output of the Neural Network Auto-Regressive model is highly confirmed with the GPS measurements. [ABSTRACT FROM AUTHOR]

GPS has become an established technique in structural health monitoring. This paper presents the application of an on-line GPS RTK system on the Zhujiang Huangpu Bridge (China) for monitoring bridge deck and towers movements. In this study, both the form and functions of movements of the deck and towers of the bridge under affecting loads were monitored in lateral, longitudinal and vertical directions. Such movements were described in time and frequency domains by determining the trend, torsion, periodical of the series using probability density function (PDF). The results of the time series GPS data are practical and useful to bridge health monitoring. [ABSTRACT FROM AUTHOR]

Abstract: This paper uses GPS monitoring system on the Yonghe Bridge. After a year from re-construction of this bridge, cracks were pronounced 48.2m far from the beginning of the abutment. To analyze the movements of bridge tower, the current operational safety, the cause of bridge cracks and sensitivity of GPS signals, and its movements were observed under different stress factors such as wind speed, temperature change and traffic loads. The observed lateral, longitudinal of bridge’s towers were studied. Two analytical methods namely; DWT and FT were used for the analysis of observation data. The analysis of test results indicates that: (1) The STFT is a significant step forward from the traditional FFT in terms of structural response analysis. (2) The sensitivity of GPS signals does not depend on the position of GPS antenna; and (3) the cracks of bridge deck bring out the frequency of the bridge tower movement transient characteristics. [Copyright &y& Elsevier]

This study deals with the viability of using a designed geometrical model consists of plane, polar coordinates (PC) and span length in the determination of bridges deformation. The data of a Tianjin Yonghe bridge located in the southern part of China as collected by RTK-DGPS technique and Accelerometer were used in the analysis. Kalman filter and last Fourier transformation (FFT) analyses were used to determine the frequency. The results indicate that the designed plane and PC geometrical model are easy to calculate the long-time structural deformation monitoring. In addition, the observed frequency using GPS with the rate of 20 Hz doesn't give correction natural frequency of the observation structures. [ABSTRACT FROM AUTHOR]