Testing and long-term monitoring of a curved concrete box girder bridge

Abstract

Abstract:Capital investment in national infrastructure is significant. The need to maintain and protect critical infrastructure links has led in recent years to significant developments in the area of structural health monitoring. The objective is to track a structure's long-term performance, typically using sensors, and to successively compare most recently measured responses with prior response history. During construction of the West Street On-Ramp, a curved concrete box girder bridge, located in the city of Anaheim (California), eleven accelerometers were permanently installed on its bridge deck. The associated data acquisition system was configured to record once a specified threshold acceleration response was exceeded; during the period 2002 -2010 a total of 1350 datasets including six earthquakes, for each of the eleven sensors, were acquired. This automatically acquired data was supplemented, during the summer of 2009, with responses measured during controlled vehicle tests. Six accelerometers were additionally installed on the frame of the weighed test vehicle. This paper presents the findings of the analyses of these measured data sets and serves to inform owners and managers as to the potential feedback from their instrumentation investment. All response histories were analyzed using frequency domain techniques for system identification. Extraction of the modal characteristics revealed a continuous reduction, of approximately 5%, in the first three natural frequencies over the period of the study. The measured responses from the vehicle sensors are discussed in the context of identifying the potential for bridge frequency measurement using instrumented vehicles.

A Study of Temperature and Aging Effects on Eigenfrequencies of Concrete Bridges for Health Monitoring

“…While some studies from literature showed that the stiffness of concrete bridge was reduced over time [7] [8] [11], others authors detected an increase [3] [4] or attacked the issue numerically [12]. Our observations of the above-mentioned sample bridge and the measurement of its first 3 eigenfrequencies show in general a decrease over the years.…”

Health Diagnostics of Highway Bridges Using Vibration Response Data

“…While abrupt changes in the dynamic properties of bridges are usually caused by a destructive event such as an earthquake, previous studies on long-term monitoring showed the natural frequencies of bridge structures follow a gradual and approximately linear decrease over the years (Soyoz and Feng 2009;Gomez, et al 2011). Such effects cannot be disregarded in an accurate structural health condition assessment.…”

Monitoring the dynamic characteristics of an urban bridge before, during and after widening

“…Currently, these methods are frequently used (e.g. Altunisik, Bayraktar, & Sevim, 2011;Brincker, Zhang, & Andersen, 2001;Gomez, Fanning, Feng, & Lee, 2011;Hadson, 1977;Jacobsen, Andersen, & Brincker, 2008;Maalek, Akbari, & Ziaei-Rad, 2010;Peeters & Ventura, 2003;Rodrigues, Brincker, & Andersen, 2004;Ubertini, Gentile, & Materazzi, 2013;Wenzel, 2009). Thus, in this study, through performing several operational modal tests and subsequent use of the well-known enhance frequency domain decomposition (EFDD) method, the dynamic characteristics of an urban bridge before, during and after widening have been identified.…”