Health Monitoring Of Concrete Bridges Research Articles

Health monitoring of concrete bridges and vehicle loads correlation analysis based on acoustic emission

In recent years, with the development of digital acoustic emission (AE) systems and the improvement of signal processing technique, acoustic emission technology has been more and more widely used in the research of dynamic processes of compression, tension, impact, fatigue, crack, and fracture of materials and structures. Since correlation analysis of vehicle loads during the monitoring period is lacking in previous concrete bridge structure health monitoring with AE, it is hard to identify the form of AE signals when vehicles cross the bridge. This paper is the first study to combine acoustic emission technique with dynamic monitoring of vehicle loads in bridge structure health monitoring. It studies the feasibility of applying AE technique to existing concrete bridges and discusses characteristic forms of acoustic emission when vehicles pass the bridge. The monitored bridge is a typical highway concrete bridge with small box girders. AE sensors were located on the web, deck plate, and bottom plate of the box girders; a weigh-in-motion system (WIM system) was located in the pavement of bridgehead. The clocks of the two systems were synchronized in order to coordinate the relationship between AE and the weight and velocity of vehicles when they pass the bridge. Based on the analysis of recorded data in 24 hours, the forms of AE signals and the influencing factors were studied; the response characteristics of AE in different locations of the box girder were detected. Then, the correlation between vehicles' dynamic loads and AE features was studied. Reference datum of healthy concrete bridges under the vehicle loads was established, which laid the foundation for further monitoring and evaluation of concrete bridges by AE.

Structural Health Monitoring of Concrete Bridges in Guilan Province Based on a Visual Inspection Method

Structural Health Monitoring of Concrete Bridges in Guilan Province Based on a Visual Inspection Method

Development of a long-term monitoring system based on FBG sensors applied to concrete bridges

Structural health monitoring has become increasingly valuable in recent years and is starting to take a leading role in the field of structural engineering. Monitoring systems based on fiber optic technology have proved to exhibit meaningful benefits when compared with the current solutions of an electric nature. However, further development of this technology is needed to achieve its efficient and widespread use in the structural health monitoring of bridges. The development of new and efficient transducers is mandatory to expand this novel technology to the field of civil engineering. This work is focused on the development and application to concrete bridges of new and reliable optical based transducers, more specifically, a vertical displacement transducer and a strain transducer to be embedded into concrete, both based on Fiber Bragg Grating (FBG) sensing technology. The conception and the development of these innovative transducers, aiming at their integration in the structural health monitoring of concrete bridges, are referred to. A field application of the developed transducers is presented invoking the advanced optical based structural monitoring system of the Lezíria Bridge. The system’s conception, the adopted sensors network architecture, and the practical installation of a monitoring system based on FBG sensors are discussed. Finally, the operation mode and the performance of the optical based structural monitoring system used for the permanent surveillance of the Lezíria Bridge are described and appraised.