Dynamic Performance Analysis of the Towers of a Long-Span Bridge Based on GPS Monitoring Technique

Abstract

The present study investigates the parameter identification and the dynamic performance of a long-span bridge tower based on the output of a global positioning system (GPS) health monitoring system. The random decrement (RD) algorithm is used to estimate the tower displacement impulse response. Three methods are applied to extract the dynamic performance including least squares complex exponential (LSCE) method, Hilbert envelope method (HEM), and eigensystem realization algorithm (ERA). Results reveal that the HEM and LSCE method are more suitable to extract fundamental frequency and modal and damping ratios of the tower. Furthermore, the dynamic properties and statistical time series analysis of the GPS measurements illustrate that the traffic loads have a high significant impact on the semistatic and dynamic performances.

Adjustment and Assessment of the Measurements of Low and High Sampling Frequencies of GPS Real-Time Monitoring of Structural Movement

“…Furthermore, the correlation coefficient between the movements of the two directions is −0.01. This result means that the effective movements of the tower occurred in the traffic direction (X-direction), as discussed in [41], and this conclusion confirms that the noise also occurred in this direction. Other previous studies [9,41,42] concluded that the traffic loads are the main loads affecting the bridge.…”

“…The output of the two rovers is the RTK time series of global Cartesian coordinates of the installed receivers in the WGS84 coordinate system. Therefore, the collected coordinate data are converted to a local BCS for the analysis of the observations [41]. In this coordinate system, the X-axis represents the traffic direction, and the Y-axis represents the lateral direction of the bridge (Figure 7b).…”

“…During the bridge inspection on August 2008, several damage patterns were detected near the south tower [39]. The dynamic performance of the bridge is studied based on a long-period monitoring system; see [39,41,42]. Moreover, the quality of the GPS observations is discussed in [41].…”

“…The dynamic performance of the bridge is studied based on a long-period monitoring system; see [39,41,42]. Moreover, the quality of the GPS observations is discussed in [41]. However, in this section, the filtering model is evaluated in damaged and undamaged cases, and the dynamic performance of the two cases is presented and discussed for the GPS installed on the south tower.…”

Recent Advances of Structures Monitoring and Evaluation Using GPS-Time Series Monitoring Systems: A Review

“…In addition, short-term positions of the measured points [26,37,39]. Data collected based on relative base station is used to measure the accurate position of the monitoring points [15,16,19,21]. Previous GPS monitoring systems are dependent on a wire system to collect data, but nowadays, wireless GPS systems are developed to decrease the monitoring cost [40][41][42][43].…”