Structural Health Monitoring of Bridges: A Study
Due to the uncertainity in mechanical and environmental loads, bridges do not necessarily behave as anticipated in design. As a result, these may undergo deterioration with respect to time. At present, there are many bridges classified as structurally deficient or functionally obsolete because of aging, insufficient design or overloading. Hence, it is necessary to implement a system for ensuring safety and detection of the evolution of damage and performance deterioration of bridges to prevent loss of economy as well as human life. The Structural Health Monitoring (SHM) system serves this purpose. It consists of determining, by measured parameters, the location and extent of damages in bridges as they happen. Through proper health monitoring, the service life of a deteriorating bridge can be extended and catastrophic events can be prevented.
The objective of the present study is to understand the basic concepts of SHM and its objectives and benefits. In the past, monitoring methods were adopted by visual inspection and tap tests which faced many problems such as tedious work, less frequency of implementation, approximate prediction of flaws, not able to determine damages due to other aspects such as corrosion of reinforcement, material degradation, connection problems, etc. This survey aims to present different methodologies adopted for health monitoring of bridges by researchers in the last two decades, in a chronological order. Also, it briefly describes the recent advancements in damage detection methods, which include the use of Acoustic Emission (AE)-based technology, Fiber-Optics based technology, vibrations-based monitoring, wireless sensing technology, GPS, Artificial Neural Network (ANN) method, etc., which resulted in much better and accurate prediction of damages and overcome the practical challenges encountered in the conventional methods through the study of peer-reviewed journals and research activities. This study will be beneficial to the researchers who will undertake investigation on damage detection of bridges, in order to have an idea on the type of damages and identification of the locations, with newer, more innovative technologies.
Keywords: Damage detection, Sensors, Steel Bridges, Dynamic Characteristics